Background: Evidence on self-care ability and occupational outcomes in Chinese survivors of childhood cancer is clearly lacking. This study aims to identify clinical and behavioral factors associated with poor life functioning in this population. Methods: This was a cross-sectional study conducted at an ambulatory clinic of a public hospital in Hong Kong. Licensed occupational therapists administered the Life Functioning Assessment Inventory on survivors diagnosed with cancer <19 years old and ≥5 years post-diagnosis. Survivors\' career development self-efficacy, subjective happiness, and motivation were evaluated using structured questionnaires. Clinical information was obtained from medical records. Multivariable linear regression was used to evaluate factors associated with life functioning outcomes, adjusting for clinically relevant variables. Results: Eighty survivors were recruited (58.7% male; age at diagnosis: 6.7 [standard deviation (SD) = 4.8] years; age at evaluation: 24.4 [SD = 6.5] years). Compared to survivors of leukemia, survivors of brain tumor performed worse in social functioning (β = -0.79, standard error [SE] = 0.36; p = 0.034). Survivors who had been treated with cranial radiation also had lower worker life functioning than those who had not (β = -0.91, SE = 0.031; p = 0.021). Higher activity motivation was significantly associated with better leisure functioning (β = 0.086, SE = 0.03; p = 0.008), social functioning (β = 0.036, SE = 0.02; p = 0.036), and career development self-efficacy (β = 1.04, SE = 0.26; p < 0.0001). Conclusion: Survivors of brain tumors and survivors who were treated with radiation have poorer life functioning, particularly in social and work domains. Future work includes validating the study findings in a larger cohort of survivors in Hong Kong. Addressing modifiable behavioral factors include motivating survivors to engage in meaningful activities that contribute to self-care and participation in society, as well as providing at-risk survivors with ongoing support from community vocational services.