Background and Study Aim The benefits of physical activity for health are well known, but sometimes we fail to put that knowledge into action. There is an ongoing decline in total physical activity (PA), especially among adolescents and young women. This decline points to the need to find more effective solutions. This study aimed to determine the relationship between physical activity and attitudes toward physical activity, and also between self-esteem, body image (as subjective variables) and body mass index (as an objective variable). Material and Methods This cross-sectional study measured and investigated 152 female students from various faculties in their first and second years of study at the Bucharest University of Economic Studies. The research utilized direct anthropometrical measurements and several self-reported instruments. These included questionnaires on self-esteem, body image, physical activity attitude, and a report on the frequency of physical activity. Conclusions Self-esteem was assessed using the Rosenberg Self-Esteem Scale. Body dissatisfaction was evaluated using the Contour Drawing Rating Scale. Results The mean Body Mass Index (BMI) value of 20.89 kg/m2 indicates a healthy, normal BMI. The mean self-esteem score (31.48) falls within the normal range, but 60% of respondents could not match their actual body shape with their ideal or desired body image. 54% of respondents reported engaging in 30 minutes of physical activity, three times a week, outside the university program. As a result, the mean value of the attitude towards physical activity is slightly positive. 33% of young women's self-esteem is related to physical factors such as body image, frequency of physical activity, and attitude towards physical activity. Self-esteem mediates the correlation between body image and physical activity frequency, and even more with students' attitudes towards physical activity. The study indicates that targeted physical education programs and consistent, independent physical activity can mitigate the challenges associated with the investigated variables.