This article reports the development and validation of the new Process and Outcomes from Service-Learning (POSL) questionnaire, a self-report measure that assesses students' service-learning experiences as well as their attainment of a comprehensive set of intended service-learning outcomes. The study involved three phases: (a) construct identification and item generation, (b) content and face validation of the draft items through expert judgment and cognitive interviews, and (c) construct validation through exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and reliability analysis. The final instrument consists of two parts. Part 1 comprises 18 items that measure students' service-learning experiences on six dimensions. Part 2 contains 14 items to assess students' learning outcomes from service-learning grouped under four dimensions. Results show that POSL is a highly reliable and reasonably valid measure of students' experiences of and outcomes from service-learning with good psychometric properties. Limitations and implications of the study are also discussed.