Tehran University of Medical Sciences Basic & Clinical Cancer Research 2228-6527 13 1 2022 01 04 72 83 Narges Abdous Department of Exercise physiology, Alzahra University, Tehran, Iran Parvaneh Nazarali Department of Exercise physiology, Alzahra University, Tehran, Iran Azam Ramezankhani Department of Physical education, Rasam higher education institute, Alborz, Iran Fateme Fallah Department of Physical education, Rasam higher education institute, Alborz, Iran 2021 05 08 2021 09 20 Background: The aim of this study was to assess the correlation between nutritional knowledge, Attitude, and Practice (KAP) and physical activity (PA) on the quality of life (QOL) in women with breast cancer (BC). Methods: This cross-sectional study involved all women with BC who referred to Imam Khomeini Hospital in Tehran during the years 2018-2019 that by using Cochran formula, 220 of them were selected by convenience sampling and answered the questionnaire including Global Physical Activity Questionnaire (GPAQ), Nutritional Knowledge, Attitude, Practice Survey (KAP) and Quality of life Questionnaire for breast cancer patients (QLQ-30). To determine the share of nutritional variables and physical activity (PA) in predicting QOL, standard multiple regression was used by SPSS 22 software. Results: The findings of the study showed that the BC patients’ PA (109.61±110.831),QOL (49.805±16.830) and KAP (K= 46.028±11.879; A=45.540±19.754; P=46.870±12.362) were not in a good condition.The best functional outcomes of QLQ-30 questionnaire were found for social functioning (73.560±26.873) and role functioning (73.560±26.873) subscales whereas emotional functioning was found lowest (58.257±24.298). Also, the results showed that Nutrition-RelatedKnowledge (β=144; P=0.036), Attitudes (β=160;P=0.038), and Practice (β=0.596; P=0.045) and PA (β=0.042; P=0.001) were significant factors in predicting cancer patients’ quality of life. Conclusion: The study showed that active patients have a good QOL, also, right nutritional choices and performance by the patients can result in a better quality of life,therefore, the patients should receive special interventions at this time. https://bccr.tums.ac.ir/index.php/bccrj/article/view/389 https://bccr.tums.ac.ir/index.php/bccrj/article/download/389/478