This study investigated metamemory knowledge related to a professional task and the relationships between metamemory knowledge and memory performance in a simulated professional task, which was a beverage-service job with memory constraints changes. Metamemory knowledge was assessed by interviewing student waiters about hypothetical recall tasks concerning lists of beverages. They then carried out a simulated beverage-service task, including a first paired-associate recall (beverage-customer), then a global recall (order to the bartender), followed by a second paired-associate recall (beverage-customer). Memory constraints were manipulated with table size and perceptive cues. Results revealed that in metamemory knowledge, task-strategy, and strategy were the only variables that were related. Metamemory knowledge produced an effect on all memory performance, whatever the constraints were. The implications of these findings for professional training are discussed in terms of strategy instruction for enhancing professional performance when memory demands change in the work environment. Copyright 1997Academic Press