Abstract Breast cancer is the most common invasive cancer and a leading cause of premature mortality for females worldwide. It accounts for 16% of all female cancers; 18.2% of all cancer deaths globally are from breast cancer. Social support plays a major role in modifying negative effect of this disease on affected individuals. It is an important psychosocial resource for coping with stressful life events. This study was carried out to examine social support as determinant of emotional adjustment of breast cancer patients after surgery in selected hospitals in Ibadan, Nigeria. This cross-sectional descriptive survey utilized a quantitative approach. A sample of two hundred and eighteen patients was randomly selected from hospitals in Ibadan. The respondents were reassured of confidentiality of the data. The instrument used basically was self-structured questionnaire. Data were collected, coded and analyzed using Pearson correlation coefficient. The respondents’ ages were between 21- 51 years; 87.2% were females, majority of them (81.6%) were Christians, more than half (62.4%) were married, about one third (31.2%) had higher qualifications, 55.0% were civil servants and 74.3% were living with other family members. Result findings show that instrumental support had significant effect on emotional adjustment of the breast cancer patients after surgery. Family and friends helping the patients had a positive effect on their emotional adjustment. Therefore, it was revealed that instrumental support had a positive effect on emotional adjustment of the patients (r.cal = .217, r. critical = .195, P < 0.05). Also, emotional support had a significant effect on emotional adjustment of the patients after surgery. Having family members and friends to talk to and help with personal problems was helpful to emotional adjustment. Thus it was evident that emotional support had a positive effect on emotional adjustment (r. cal = .250, r. critical = .195, P < 0.05) The patients admitted that they had friends and family members who helped them and were a source of comfort to them. This helped them to show a better psychological and emotional adjustment to breast cancer than those who did not have support. It is recommended that adequate attention be given to financial, material and emotional needs of the breast cancer patient. Keywords: Social support, determinant, emotional adjustment, breast cancer patients. Citation Format: Christiana Oluseun Oyewusi, Samuel Oyebode Oyewusi. Social support as emotional adjustment determinant of breast cancer patients after surgery in selected hospitals in Nigeria. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3457.