Life in residential care can be challenging for residents and staff. Bringing humor into this setting may benefit residents, creating a more productive, enjoyable work environment for staff. The potential effect of exposure to humor therapy on staff, both as active and incidental participants, as part of a randomized controlled trial of the effect of humor therapy for aged care residents was investigated in the Sydney Multisite Intervention of LaughterBosses and ElderClowns (SMILE). The intervention involved a humor program with professional performers (ElderClowns) and trained facility staff (LaughterBosses) for a minimum of nine 2-hour sessions over 12 weeks. Methods included a staff survey at three time points, interviews with LaughterBosses, and a satisfaction rating by facility managers. There were significant positive findings for some staff subgroups, including assistants in nursing/personal care assistants and staff older than 45. LaughterBoss interviews and intervention group manager ratings of staff work enthusiasm were positive.