To assess physical activity (PA) and its determinants in breast cancer survivors (BCS), attending a Tunisian hospital, as well as to assess their quality of life (QOL) and examine the relationship between PA and BCS'QOL. We conducted a cross-sectional study among BCS attending the outpatient oncology, gynecology and radiotherapy clinics at a Tunisian hospital in April 2022 using a self-administered questionnaire. The valid Arabic version of the International Physical Activity. Questionnaire short version was used to assess PA and sitting time. QOL was assessed using the valid Arabic version of the 12-item Short-Form health survey. A total of 95 BCS were recruited. BCS reported overall moderate PA levels with a median MET of 1440 (IQR 680- 2400) minutes/week and a mean total sitting time of 281.79±134.36 minutes/day. Overall, patients aged 50 years and above had significantly lower levels of sitting time (231.43±129.32vs 332.14±121.63, p= 0.04). Similarly, subjects aged 50 years and above, and of rural origin had higher levels of PA (1908.5 (IQR 939.7-3268.5) vs. 1266 (IQR 471-2946), p= 0.114 and 1788.5 (IQR 1072.5-3252) vs. 1440 (IQR 537-3057), p= 0.259 respectively). Regarding BCS'QOL, they showed moderate disability in the physical component (39.3 ±7.08) , and mild disability in the mental component (43.94 ±9.23). BCS' QOL was significantly correlated to PA (r=0,258, p=0,012). Adherence to regular PA is effective in improving BC patients' survival rate. Therefore, to enhance survivors' QOL, a healthy lifestyle including regular PA is well recommended.