Introduction: Cancer diagnosis may shift an individual’s food choices as well as self-esteem mainly due to the side effects of treatment, which will influence their nutritional status and perception about themselves. The aim of this study was to explore the association between dietary changes and self-esteem among cancer patients. Methods: A cross-sectional study was conducted among 113 cancer patients in Hospital Universiti Sains Malaysia. Among the data collected were socio-demographic background, clinical characteristics, Karnofsky Performance Status Scale, dietary changes questionnaire before and after cancer diagnosis, self-esteem. Spearman correlation was employed for determining the relationship between dietary changes and self-esteem. Results: Out of 113 subjects, 98 subjects (86.7%) made changes in their dietary intake after being diagnosed with cancer. A total of 58.4% and 45.1% of the subjects reported a decrease in their intake of sugar and condensed milk, while 52.2% stopped consuming red meat. The mean self-esteem score was reported to be average (29.33 ± 3.52). However, no statistically significant association was found between socio-demographic, clinical parameters, and self-esteem with dietary changes. Conclusion:The findings of this study demonstrated that cancer patients had made drastic dietary changes following cancer diagnosis especially consumption of red meat and food high in sugar. Most cancer patients had average self-esteem level. Although no association had been found between dietary changes and self-esteem level, it is suggested for more studies should be carried out to provide clear understanding of the factors affecting dietary changes among cancer patients.