Background and Objectives: The purpose of this study was to study the relationship between self-estimated and measured physical fitness among non-athletic young females and males. Material and Methods: The target population of this study was all non-athletic male of female students from the University of Guilan. After translating the SPQ standard-questionnaire (Delignieres, 1994) and adjusting some of the questions, the questionnaire was evaluated by the specialists in the context of validity and the Reliability achieved by test-retest (Cronbach Alpha value of 0.84) We then, according to the Odineski table selected 150 male and 170 female students, with the mean: age of 21.83 ± 1.17 and 21.13 ± 1.56 years height of 173.64 ± 1.56 and 159.29 ± 6.45 cm weight of 70.66 ± 11.80 and 57.73 ± 10.27 kg and body mass index of 23.45 ± 3.3 and 22.74 ± 3.7 kg/m2, respectively. The inferential statistics of the t–test and Pearson correlation coefficient were used for data analysis. Results: The results show that male and female students in the study did not have a true self-estimate of their physical fitness, muscular strength, endurance cardio – respiratory, flexibility, and body composition. There were also significant differences between self-estimated physical fitness and the fitness test measures among the male and female students (P<0.001). Compared to the female students, the male students had a better self-estimated image of their physical activity. Conclusion: Based on the fact that the male and female students in the study do not have a true self-estimate of their physical fitness, we suggest that they should be provided with necessary facilities and support in order to encourage them to participate in the physical activity and fitness training programs, which could lead to improvement of their mental and body health status and a better picture of self-estimated physical activity.