The purpose of the study was designed to examine the effect of fartlek training on cardiovascular endurance and speed endurance of university men students. For the purpose of the study, thirty men students from Mother Terasa College of Physical Education, Mettusalai, Pudukkottai, were selected as subjects. They were divided into two equal groups. Each group consisted of fifteen subjects. Group I underwent fartlek training for three days per week for twelve weeks. Group II acted as a control and did not undergo any special training programme apart from their regular physical education programme. The following variables namely cardiovascular endurance and speed endurance were selected as criterion variables. All the subjects of the two groups were tested on selected dependent variables by using Cooper’s 12 min run and walk test and 150 mts run respectively at prior to and immediately after the training programme. The analysis of covariance was used to analyze the significant difference if any among the groups. The .05 level of confidence was fixed as the level of significance to test the ‘F’ ratio obtained by the analysis of covariance, which was considered appropriate. The results of the study showed that there was a significant difference between the fartlek training group and the control group on cardiovascular endurance and speed endurance. And also it was found that there was a significant improvement in cardiovascular endurance and speed endurance due to twelve weeks of fartlek training.