This paper provides an overview of Direct Integrity Testing for Pressure-Based Tests. Membrane Integrity Testing has become the means of determining compliance with regulations. Testing pressure for pressure-based direct Integrity Testing is the most important parameter. The full-scale challenge test is the best indicator for the sensitivity and reliability of an Integrity Test method. Testing frequency should be based on a risk-based approach that embraces both the occurrence and consequences of an integrity breach. The probable occurrence of and integrity breach can be determined through durability tests and/or data from existing plants. Membrane systems that have an easy means to locate and repair the breach can save time and improve plant productivity.