Chemotherapy in cancer treatment has a debilitating effect on the patients despite its effectiveness. However, less focus has been on understanding how patients self-manage the symptoms experienced after out-patient chemotherapy. This prompted the researchers to explore the symptoms self-management used by cancer patient undergoing chemotherapy in selected tertiary health institution in South-West, Nigeria. A cross sectional survey research design was used to gather data in the three selected tertiary institution in South-West, Nigeria. From a total of 640 cancer patients undergoing cancer treatment in these hospitals, a sample size of 443 respondents was determined using Cochran formula. A response rate of 94. 8% was achieved. Analysis of data was done using descriptive statistics of frequency, percentage, standard deviation. Results shows that the most used symptoms self-management strategy was medications prescribed by healthcare providers (24.7%) while the least was over-the-counter medications (2.7%). Counselling from healthcare workers (26.7%) was the most influential factor influencing the adoption of symptom management strategies while cultural belief was the least (1.9%). Overall, cancer patients take a nuanced approach in managing the chemotherapy symptoms, where personal, economic, cultural, and social factors are all integrated into their decision-making process (mean score = 4.33, on a scale of 10) In conclusion, the study identified the symptoms self-management strategies used by patients with cancer undergoing chemotherapy in selected tertiary health institutions in south-west, Nigeria. The study recommended that nurses must be intentional in counselling the cancer patients undergoing chemotherapy.