OBJECTIVE: To assess the intratubal pressure (ITP) and patency status of the fallopian tubes before and after transcervical catheterization of the fallopian tubes (TCFT). DESIGN: Prospective procedural assessment. SETTING: Pope Paul VI Institute for the Study of Human Reproduction. PATIENT(S): Two hundred thirty-four women with either primary or secondary infertility. INTERVENTION(S): Patients underwent selective hysterosalpingography and, in some cases, TCFT with measurement of the ITP before and after the procedure. MAIN OUTCOME MEASURE(S): The ITP before and after TCFT. RESULT(S): The mean (+/-SD) ITP in freely patent tubes was 0.53 +/- 0.06 atm, that in partially obstructed tubes was 1.23 +/- 0.52 atm, and that in completely obstructed tubes was 2.79 +/- 1.40 atm. After TCFT, the mean (+/-SD) ITP in partially obstructed tubes decreased to 0.64 +/- 0.31 atm and that in completely obstructed tubes decreased to 1.86 +/- 1.35 atm. The ITP was normalized in 76% of partially obstructed tubes and in 29.5% of completely obstructed tubes. In all cases of complete obstruction in which surgical correction was attempted, organic pathology was identified. CONCLUSION(S): The procedure described is a safe and easy means of obtaining reliable and significant information on the status of the proximal fallopian tube.