['To evaluate the effect of individual providers on pregnancy outcome after embryo transfer.', 'Retrospective data analysis.', 'University-based tertiary-care assisted reproductive technology program with 10 physician-providers.', 'Six hundred and seventeen women who underwent 854 fresh embryo transfers between January 1996 and January 1999.', 'Pregnancies after embryo transfer were recorded for each provider.', 'Establishment of a clinical pregnancy.', 'Three hundred ninety-three clinical pregnancies resulted from 854 embryo transfers, for an overall clinical pregnancy rate of 46.0% per embryo transfer. Three hundred forty-seven (40.6%) pregnancies were ongoing. The clinical pregnancy rate varied significantly between providers: for example, 17.0% (47 transfers) vs. 54.3% (57 transfers) (P<.05). Similarly, the ratio of high-grade embryos required to produce a gestational sac differed between providers. The number or quality of embryos transferred did not differ significantly.'] Do pregnancy rates after embryo transfer depend on the provider at embryo transfer?