Objectives: To quantitate and compare granulosa cell alpha-inhibin messenger RNA (mRNA) levels in IVF-ET poor and good responders and thereby learn how alpha-inhibin mRNA levels change in states of diminished ovarian responsiveness. Design: Ribonucleic acid analysis of stored luteinized granulosa cell samples. Setting: Academic tertiary care institution. Patients: Fifty-three women undergoing follicle aspiration for IVF-ET were studied. Patients were classified as poor responders (n = 16) or good responders (n = 37) according to their E(2) concentration on the day of hCG; the E(2) of poor responders was <1,000 pg/mL (3,671 pmol/L) and that of good responders was greater than or equal to 1,000 pg/mL (3,671 pmol/L). Main Outcome Measures: Messenger RNA levels were measured using dot blot RNA analysis. The following parameters were determined or derived: total mRNA levels, total alpha-inhibin mRNA levels, alpha-inhibin mRNA per follicle, and proportional alpha-inhibin mRNA as the ratio of alpha-inhibin mRNA:total mRNA. Results: Proportional alpha-inhibin mRNA and alpha-inhibin mRNA per follicle were not significantly different between poor responders and good responders. Total mRNA and total alpha-inhibin mRNA levels, however, were diminished significantly in poor responders. Conclusions: The observations that proportional alpha-inhibin mRNA and alpha-inhibin mRNA per follicle do not significantly change in poor responders, whereas total alpha-inhibin mRNA does, indicate that the decrease in total alpha-inhibin mRNA in poor responders reflects a decreased pool of total mRNA, likely because of a reduction in follicle number. These findings are in contrast to other recent reports that describe a change in granulosa cell function accompanying states of decreased ovarian responsiveness.