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The centrifugation of bovine sperm in the 45-90% Percoll gradient is a technique used in in vitro fertilization. The objectives of the study were: to determine the percentages of sperm with positive endosmosis (PE) and negative (NE), individual motility (IM), viability (alive and dead) and normal head and tail morphology at different centrifugation times. The HOST test was used for cell endosmosis, the eosinnigrosin staining for viability and the Minitube Spermac staining for the morphology. Four treatments were evaluated with six repetitions: thawed and centrifuged semen in 45-90% Percoll gradient for 5, 10 and 15 minutes and thawed semen only (control). For the HOST test, the percentages of PE for the 15, 10 and 5 minute centrifugation times were similar with values of 73.92%, 75.19% and 73.63% respectively, however, these differ from the control with 65.11% (P=0.05); the IM percentages for the 15, 10 and 5 minute centrifugation times were 92.00%, 93.00% and 91.50%, being similar to each other, but these differ from the control with 69.5% (P=0.05). The viability was 71.32%, 71.42% and 73.56% for the times of 15, 10 and 5 minutes respectively and they differed from the control with 56.63% (P=0.05). In normal head and tail morphology, there were no significant differences (P>0.05) with values higher than 92% and 82% respectively. It is concluded that centrifugation during 5, 10 or 15 minutes when performing the 45-90% Percoll gradient, does not affect the integrity of the plasma membrane of bovine sperm. [ABSTRACT FROM AUTHOR]