We examined the effects of framing and missing information in experts and novices. The present study attempted to show the effect of framing, examined whether experts are less affected by the framing effect than are novices, and examined the differences between experts and novices in the way they respond to complete and missing information. A gambling task was used in which subjects rated their likelihood of taking a gamble on the basis of payoff or chance information, or both. Results showed a significant framing effect; that is, subjects are more likely to take a gamble if it is framed positively than if it is framed negatively. We found that experts and novices are similarly affected by framing but that novices attach more weight to chance information than do experts. Overall, analyses showed no significant difference in the way experts and novices respond to complete and incomplete information.