Objective: To analyze the usefulness of rapid HIV testing in pregnant patients in the delivery room. Methods: This prospective study compared a rapid test and a fourth-generation enzyme-linked immunoassay (ELISA) for HIV screening among pregnant patients admitted in labor with an unknown HIV status at a university hospital in Mexico between July 2015 and February 2016. Pearson correlation analysis was performed, and the diagnostic accuracy of the two tests was assessed with HIV RNA polymerase chain reaction (PCR) as the reference method. Results: Overall, 534 patients were included. With a signal-to-cutoff (S/CO) value of 1.0 or more as a diagnostic criterion, 6 (1.1%) patients had a positive ELISA result. Three had a negative rapid test and three had a positive test (r=0.705). With an S/CO value of 2.0 or more as cutoff, 4 (0.7%) patients had a positive ELISA result. Three had a positive rapid test and one had a negative test (r=0.865). Only three of six patients with an S/CO of 1.0 or more were confirmed to have HIV by RNA PCR. Conclusion: The rapid test showed a strong correlation with the fourth-generation ELISA. Therefore, rapid testing is a useful tool in the delivery room for patients with unknown HIV status.