<p>This study aimed to analyze household participation in waste source separation relative to the availability of waste collection services in the Western Province of Sri Lanka, focusing on Attanagalla Pradesheeya Sabha. Data were collected from 300 households, equally distributed between serviced and no-serviced areas, utilizing a structured questionnaire and a 5-point Likert scale to assess opinions on waste segregation. The analysis identified a significant disparity in source separation practices: 66% of households in serviced areas participated in waste separation, compared to 97% in no-serviced areas. Time constraints were the main barrier in serviced areas, while a lack of knowledge was the chief obstacle in no-serviced areas. Additionally, 60% of households in serviced areas were willing to pay for waste collection services, against 85% in non-serviced areas willing to pay for efficient waste management. The findings highlight the need for targeted awareness programs and infrastructure improvements, especially in no-serviced areas. This study offers policymakers insights to design targeted interventions that improve waste separation behaviors, enhancing municipal waste management and promoting environmental sustainability in semi-urban Sri Lanka.</p>