Background More research is required to understand the effects of implementing structured goal-setting on trainee engagement in competency-based clinical learning environments. Objective To explore how residents experienced a rotation-specific goal-setting intervention on geriatric medicine rotations at 2 hospitals. Methods All rotating residents were expected to complete the intervention, consisting of a SMART-based (Specific, Measurable, Achievable, Relevant, and Time-Bound) goal-setting form and feedback sessions with teaching faculty. From November 2019 to June 2021, we recruited a convenience sample of rotating residents. Study participants completed pre- and postrotation 35-item Dutch Residency Educational Climate Test (D-RECT) questionnaires to compare scores from their rotation before the geriatric rotation and a postrotation semistructured interview, which we transcribed and analyzed using principles of constant comparison and reflexive thematic analysis. Results We interviewed 12 of 58 (20.7%) residents participating in the goal-setting intervention, 11 of whom completed both D-RECT questionnaires. Participants' D-RECT scores favored the geriatric medicine rotation versus the immediately preceding clinical rotation (M=4.29±0.37; M=3.84±0.44, P=.002). Analyses of interview transcripts yielded 3 themes on how participants perceived the intervention influenced their learning experience: (1) structured forms and processes mediate, inform, and constrain goal selection; (2) interactions with faculty, patients, and system factors influenced goal enactment; and (3) unstructured assessments led to uncertainty around goal achievement. Challenges included time restrictions and unpredictable clinical opportunities. Conclusions Goal-setting appeared to help many residents direct their learning efforts and engage in collaborative processes with teaching faculty. We identified challenges limiting residents' engagement with the goal-setting intervention, which may inform the practical implementation of goal-setting in other competency-based curricula.