The current study compared perceived language gains between learners of different preprogram proficiencies, academic interests, and genders who participated in the same predeparture preparation and short-stay service learning program abroad. L2 learners studying Spanish and computer science students participated in a semester-long program to design two 1-week technology summer camps for middle school students in the Dominican Republic, followed by a sojourn to the site where participants led all camp learning and social activities. Representative statements from the "NCSSFL-ACTFL Can-Do Statements" (2015) were used to measure students' self-assessed predeparture and postdeparture ability in the three modes of communication (interpersonal speaking, interpretive listening, and presentational speaking). Results demonstrated a statistically significant difference in self-assessed language gain across the modes, with females and students with a higher predeparture proficiency reporting greater gains in perceived language development. Implications for instructional design and implementation of short-term study abroad are discussed.