In recent years, there has been an increasing interest in psychological need satisfaction and its role in promoting optimal functioning. The DRAMMA model integrates existing need and recovery models to explain why leisure is connected to optimal functioning (i.e., high well-being and low ill-being). It encompasses six psychological needs: detachment, relaxation, autonomy, mastery, meaning, and affiliation (DRAMMA). While the individual needs of the DRAMMA model have been previously shown to relate to different aspects of optimal functioning, a longitudinal study examining the entire model has not been conducted before. In this longitudinal field study covering leisure and work episodes, we tested the within-person reliability and (construct and criterion) validity of the operationalization of the DRAMMA model in a sample of 279 German employees. Participants filled out measures of DRAMMA need satisfaction and optimal functioning at five measurement times before, during, and after vacation periods in 2016 and 2017. The six-factor model showed good fit to the data. In the multilevel models, relaxation, detachment, autonomy, and mastery had the most consistent within-person effects on optimal functioning, while the relationships between optimal functioning, meaning, and affiliation were considerably weaker. In conclusion, DRAMMA need satisfaction can aid and nurture employees’ optimal functioning.