[en] A comparative research was made on the effects of total irradiation with different dosis of X-rays on the sperm morphological of rabbits. Forty adult male rabbits of the white New Zealand breed were used as experimental animals, divided in four groups of 10 animals each, being one group used as control and the others irradiated respectively with 50, 200 and 600 rad. A 4 MeV linear accelerator was used as radiation source. Semen samples evaluations were made before irradiation and in subsequent periods of 7 hours, 3 days and 1, 2, 4, 8 and 12 weeks. Sperm morphology was examined by counting 200 cells in each of 241 smears stained by William's method and in 241 formol saline preparations in phase contrast microscope. Averages and standard deviations of these data are presented. Percentages of main abnormalities and the period in which they occured are also presented. Mean percentages of normal sperm and spermatic abnormalities are given an determined at successive intervals after erradiation, a decrease in number of normal and an increase in abnormal sperm were observed. The level of sperm abnormalities was more sensitive accordingly to higher of X-rays irradiation