It is possible to customise Customise JIRA For Test Case Management without needing any third-party tools, or you can integrate with any of the following test case managers:
Zephyr Test Management System
Pitch: Zephyr provides end-to-end management of the testing lifecycle in the test department including resources, releases and sprints, test cases, scheduling, test execution, defects, documents, collaboration and all aspects of reporting and metrics in real-time. Built on an extensible management platform, Zephyr allows users to leverage their existing tool investments by providing seamless integration with popular defect tracking systems like JIRA and interoperating with commercial, open source or home grown automation tools.
Integration: Full 2-way integration with JIRA, featuring live testing dashboards that display real time metrics about your JIRA issues along side your test creation and execution status for a comprehensive "single pane of glass" view.
More details on the Zephyr JIRA plugin page.
ApTest Manager
Pitch: Affordable test management for software and hardware QA projects to improve consistency, organization, and control throughout the testing process.
Integration: Uses the JIRA SOAP API to automatically populate a new bug with information from the execution of a test and links the test execution to the associated JIRA issue. Integration module is included at no charge - see the ApTest/JIRA FAQ entry for details.
More details on Aptest Manager integration here.
Jite
Pitch: If you miss control over test execution, if you are looking for a user friendly, cheap, simple but effective functional test management tool, if you need to integrate it with Jira, and you want to do it as soon as possible, here is the right tool.
Integration: Uses the JIRA SOAP API to automatically create test-sessions to be executed on a set of tests related to jira issues. The tests loaded are selected by using a Jira filter. Many integration and automation features available. See the http://www.prismasw.it/ita/jite/indexEng.html for more details ( Video-Tutorials available ) .
More details on Jite integration here.
QaTraq
Pitch: QaTraq is the world's most popular test management tool. QaTraq provides a solid foundation for teams to create and update scripts, cases and case results, with instant access to a variety of reports, improving visibility of your testing and pin-pointing test case execution progress.
Integration: No direct integration, but you can enter the URL for one or more JIRA bugs directly in the test case.
More details on QaTraq integration here.
SpiraTest
Pitch: Complete Quality Assurance solution that manages requirements, tests, bugs and issues in one environment, with complete traceability from inception to completion.
Integration: With the JIRA connector activated, any defects logged during a test execution get routed to JIRA using the SOAP API. Any changes to these issues in JIRA then get synchronized back into SpiraTest using our SOAP API.
More details on SpiraTest integration here.
TestLink
Pitch: Free, open source testing tool to create and manage test cases and organise them into test plans. These plans allow team members to execute test cases and track test results dynamically, generate reports, trace software requirements, prioritize and assign tasks.
Integration: Adds a bug tracking interface to JIRA inside TestLink.
More details on TestLink integration here.
TestLog
Pitch: Create and manage your entire test plan, from test cases to progress reports, and more.
Integration: Can add and view JIRA issues when executing test plans, with JIRA issue keys stored in the TestLog case records - see forums discussion. Specifically, add http://hostname:port/browse/ to the "View bug" path and http://hostname:port/secure/CreateIssue.jspa to the "Add bug" path of the TestLog options.
More details on TestLog integration here.
Borland Silk
Pitch: The Go2Group JaS Plugin allows collaboration between Atlassian's JIRA issue management system and Borland's SilkCentral test case tool.
Integration: When editing an issue, JIRA will display a list of available Silk test cases in the custom field called SilkTestCases. Select one or more test cases to associate with the issue. When viewing an issue, JIRA will display information about each associated test case in an issue tab panel.
More details on Borland Silk integration here.
Mercury Test Director - HP Quality Centre
Pitch: Panel to interface with the Mercury Quality Center.
More details on Mercury Test Director integration here.
Testuff
Pitch: Testuff is an on-demand test management service that integrates with JIRA. Amongst the standard features, it also includes a test video recorder. The recorder captures bugs as they happen during testing and allows you to send the videos to your developers, making the "works for me" excuse obsolete. All in all Testuff is very easy and intuitive to use, even a beginner tester could get fully working on it within an hour.
Integration: Exports bugs found during test runs directly to the relevant project in JIRA with your JIRA user.
More details on Testuff integration here.
SQA Design / Qualify
Pitch: SQA Design is a powerful test case management solution that now integrates with JIRA. I think you'll find this tool easy to setup, intuitive to use, & powerful in it's feature set. It provides the ability to link test items (test cases, scenarios, and test plans) to issues in JIRA. You can also submit defects directly from Qualify.
More details on SQA Design integration here.