['To predict the chance of total fertilization failure (TFF) before the day of ovum pickup with known semen and female variables.', 'A statistical model was constructed to predict TFF by retrospective analysis (2,366 couples) and subsequently tested on a new IVF population (917 couples).', 'Academic tertiary referral center.', 'Three thousand three hundred eighty-three couples who underwent an IVF-ET treatment.', 'None.', 'The ability to predict the probability of TFF in IVF.', 'Two variables-postwash total progressively motile sperm cell count (postwash TPMC) and number of follicles-were found to be significant. Taking a probability of 25% as an acceptable risk of TFF, we calculated that a postwash TPMC of <1.1 x 10(6) cells results in a risk of TFF of >25%. Low responders (<4 follicles) needed a postwash TPMC of >2.2 x 10(6) cells to reduce the risk of TFF to <25%. High responders (>15 follicles) needed only 0.35 x 10(6) postwash progressively motile spermatozoa.'] Is the postwash total progressively motile sperm cell count a reliable predictor of total fertilization failure during in vitro fertilization treatment?