Service-learning was introduced into Hong Kong over a decade ago, yet there is a research gap about the self-perceived developmental outcomes for students, partly due to the lack of a reliable measurement instrument across course disciplines and types of service-learning. This study validated a recently created Service-Learning Outcomes Measurement Scale (S-LOMS) through confirmatory factor analysis (CFA) with data from 629 students. S-LOMS measures self-perceived student development through 56 items, which cover outcome domains under four overarching categories: knowledge application, personal and professional skills, civic orientation and engagement, and self-awareness. Alternative measurement models were compared in this validation exercise, with the results indicating that although a model with 11 domains and without overarching categories was preferred, there was also support for a model with 10 domains subsumed under the four abovementioned overarching categories. Multisample analyses indicated that both models were stable across gender. The practical implication of our findings is that for the purpose of measuring the developmental impacts on students of engaging in service-learning, S-LOMS offers investigators a number of options besides using the entire 56-item scale. Some administrative options are described at the end of the paper.