Purpose <p>This study sought to describe the methods of detection (MOD), their determinants and association with type of treatments received for breast, cervical and prostate cancers using a population-based cancer registry in Nigeria.</p> Methods <p>The study analyzed incident breast (<i>n</i> = 205), cervical (<i>n</i> = 147), and prostate (<i>n</i> = 250) cancers from the Edo–Benin Cancer Registry (EBCR) from 2016 to 2018. The MOD was assigned as health check-up detected or clinically detected. Case proportion ratios (CPR) were used to compare MOD across determinant levels. Statistical association between demographic determinants and MOD were assessed using binomial regression.</p> Results <p>Among the cancers recorded by the EBCR, 46% of breast (<i>n</i> = 205), 43% of cervical (<i>n</i> = 146), and 50% of prostate (<i>n</i> = 250) cases were identified through health check-ups. MOD was not significantly linked to age or marital status. Health check-ups were less common in those with less than tertiary education [breast, CPR 0.61 (95% CI 0.46–0.80), cervical, CPR 0.73 (95% CI 0.49–1.08), prostate, CPR 0.64 (95% CI 0.50–0.82)]. Significantly, more cancers detected via health check-ups were assigned to palliative care compared to clinical detection (breast: 76% vs. 58%, cervical: 80% vs. 59%, prostate: 83% vs. 64%).</p> Conclusion <p>Health check-up campaigns are a key source of new cases in EBCR, but cancers detected through them are more often assigned to palliative care than those detected clinically. The findings suggest that efforts at early detection are not expressed in treatments assignment. Pre-symptomatic individuals should be encouraged to participate in health check-ups and proper treatment made available to improve these programmes.</p>