Postthaw survival of spermatozoa with high motility and vitality is required for successful artificial insemination. The aim of this study was to compare the effects of two different thawing methods on motility, morphology, kinematic parameters, and viability of spermatozoa with a computer-assisted semen analyzer (CASA). Frozen bull spermatozoa were thawed by using two different thawing procedures: 1) Water bath; straws were thawed in a water bath at 37 degrees C for 30 s. 2) Dry thawing system; straws were thawed in a dry thawing device at 37 degrees C for 30 s. A total of 10 straws were used for each thawing procedure. There were significant differences between the thawing methods for acrosome defects (P < 0.05), head defects (P < 0.0001), middle part defects (P < 0.05), and total abnormal spermatozoa rates (P < 0.05). There was no difference between the thawing methods for total and progressive sperm motility determined with CASA. There were significant differences (P < 0.05) between the thawing methods for STR and ALH values which were kinematic parameters. The STR (66.37%) and ALH (3,28 mu m) values of dry system were higher (P < 0.05) than the STR (57.88%) and ALH (2.78 mu m) values of water bath. In conclusion, the present study demonstrated the possibility of using dry thawing system as alternative to water bath for thawing bull sperm because some postthaw sperm values obtained when dry thawing system was used were better than those obtained when water bath was used.