PURPOSE: Prolonged treatment delay often leads to adverse cancer prognosis. However, the demographic and clinical predictors of higher treatment delay burden in the Philippines have not been thoroughly evaluated. METHODS: We conducted a population-based retrospective cohort study on patients diagnosed with common cancers who received cancer treatment, to quantify the burden of prolonged treatment delay in the Philippines among this population. We analyzed 20,654 patients with common cancers from the Department of Health-Rizal Cancer Registry. The Poisson regression model with robust variance was used to identify demographic and clinical predictors of prolonged treatment delay. In addition, we examined the associations among those receiving different initial treatment types, including surgery, radiotherapy, and chemotherapy. RESULTS: We found 35.1 % of the studied cancer patients experienced initial treatment delay of more than 30 days, as well as 25.2 % and 20.0 % experiencing treatment delays exceeding 60 and 90 days, respectively. We found higher risk of prolonged treatment delay of more than 90 days in those with 0-19 years of age at diagnosis, male gender, cancer treatment at non-private hospitals, diagnoses during the 1990s, more advanced cancer stages, and non-surgical initial treatments. For patients with surgery as the initial treatment, younger age at cancer diagnosis was not significantly associated with increased burden of prolonged treatment delay, unlike for those initially treated with radiotherapy or chemotherapy. CONCLUSION: By identifying the characteristics of treated cancer patients with higher risk of protracted treatment delay, our findings will inform the national cancer control program to especially target those patients for treatment delay reduction.