We know little about what determines an effective placement experience, yet vocational placements are an integral part of many professional degree programmes. The aim of this research was to examine the influence of job (task variety, task identity, task significance, feedback, and autonomy) and supervisor (relationship quality and mentoring) characteristics on placement outcomes. The findings were tested on samples from two professions for which placement were a compulsory part of their course. Sample 1 consisted of 266 undergraduate nurses, and sample 2 consisted of 176 postgraduate psychologists. The findings showed that job and supervisor characteristics explained unique variance in professional development and placement satisfaction. Of the five job characteristics examined, skill variety, feedback from the job, and task significance influenced placement outcomes. Mentoring emerged as the most important supervisor characteristic that was associated with professional development and placement satisfaction, and to a slightly less extent, supervisor-student relationship quality was also important. The research and practical implications of the findings were discussed.