Two models of Person x Situation interaction wee examined. The first model predicts that there is a relation between personality and the situations people naturally choose to be in; the second model predicts that when there is congruence between the situation and personality, a person will experience more positive and less negative affect. These models were investigated by using mood and activity reports gathered on 3,512 occasions sampled randomly from the everyday lives of 42 subjects. Situational dimensions were related to some but not all personality variables investigated. Need for order predicted choice of typical situations and extraversion correlated with time spent recreating socially. However, it was found that individuals did not spend more time in those settings where they experienced more positive emotions nor less time in those situations where they experienced more negative affect. In terms of the affect-congruence model, several predicted relations wee found, but several others did not reach significance. The failure of the affect-congruence model to be consistently supported was probably because the affect of individuals was relatively consistent across situations. The present results suggest that although some theoretically meaningful Person x Situation interactions do occur, they are not necessarily strong or easily predictable.