OBJECTIVE To evaluate the effectiveness of transvaginal manual therapy of the pelvic floor musculature (Thiele massage) in symptomatic female patients with interstitial cystitis and high-tone dysfunction of the pelvic floor. METHODS A total of 21 women with documented interstitial cystitis and high-tone pelvic floor dysfunction underwent transvaginal massage using the Thiele technique twice a week for 5 weeks. Symptoms were evaluated before massage, at protocol conclusion, and at a mean of 4.5 months after therapy completion (long-term follow-up). The response to treatment was evaluated through the O'Leary-Sant Interstitial Cystitis Symptom and Problem Indexes, Likert Visual Analogue Scales for urgency and pain, and Short-Form 12-item (SF-12) Quality-of-Life Scale, and through changes in the physical examination findings using a 5-point modified Oxford Scale to document pelvic floor tenderness. RESULTS A statistically significant improvement was seen in the Symptom and Problem Indexes of the O'Leary-Sant Questionnaire (P = 0.015 and P = 0.039, respectively), Likert Visual Analogue Scales for urgency and pain (P = 0.001 and P = 0.005, respectively), the Physical and Mental Component Summary from the SF-12 Quality-of-Life Scale (P = 0.049 and P = 0.044, respectively), and the modified Oxford Scale (P <0.05) after protocol completion. At long-term follow-up, the O'Leary-Sant Interstitial Cystitis Symptom and Problem Indexes (P = 0.049 and P = 0.02, respectively), Likert Visual Analogue Scales for urgency and pain (P = 0.004 and P = 0.005, respectively), and modified Oxford Scale for three of four muscles in the pelvic floor (P <0.05) remained significantly improved. CONCLUSIONS Thiele massage appears to be very helpful in improving irritative bladder symptoms in patients with interstitial cystitis and high-tone pelvic floor dysfunction in addition to decreasing pelvic floor muscle tone.