Resistance training is a general term used to describe a number of different training goals such as training for improved performance, hypertrophy and increased fitness for a variety of sports. The purpose of this study was to investigate the effect of 12 week resistance exercise training on selected physical fitness variables (muscle strength, explosive power, running speed and shooting accuracy) of male handball players of Debre Birhan University. Experimental design was conducted among 24 under-graduate male players, with age group between 19 – 22 years were selected by convenience sampling technique from Debre Birhan University male handball players. The selected subjects were divided into 2 groups (control and experimental groups) randomly, each group consisting of 12 players. The experimental group underwent 12 weeks planned resistance exercise training program, three days per week and the duration was 40 minutes while, the control group continued with their regular training. Pre-test and post tests were conducted on the selected physical fitness variables such as 1RM test, vertical and broad jump test, 30 meter speed test and shooting accuracy test, each subject was tested at the same time of day. The data collected from the study subject was analyzed using SPSS software version 23.0 by paired t-test with level of significant 0.05. The results showed resistance Exercise training significantly improved muscle strength, explosive power, running speed and shooting accuracy in Experimental Group at (p<0.05). No significant differences were found in all of the variables in Control Group (p>0.05). Based on this finding, it can be concluded that 12 weeks resistance exercise training has positive effect on improvement of physical fitness and shooting accuracy variables. These data suggest that 12-week resistance training, when incorporated into a regular training session, can provide greater physical fitness variables improvements for male handball players.