Stress urinary incontinence, defined as involuntary loss of urine secondary to an increase in abdominal pressure, represents one of the most significant urological problems. Several animal models to simulate stress urinary incontinence have been presented, including methods to quantify leak point pressure. We have modified an existing leak point pressure procedure to longitudinally quantify stress urinary incontinence in rats by introducing the port a cath system. Reproducible leak point pressure measurements were carried out over a period of more than 40 days at different bladder volumes. Leak point pressure neither showed a significant relationship with the number of times anesthesia was applied nor a significant change over time. The port a cath system provided a reliable, sensitive device for longitudinal urinary bladder pressure measurements in animals with an implanted bladder catheter. This set-up therefore enables the evaluation of bladder pressure in different models for stress urinary incontinence, such as vaginal distention or pudendal transection over long periods of time within the same animal.