This study investigated to what extent, and under what circumstances, pair collaboration influences the realism in eyewitness confidence in event memory. The participants first saw a short film clip and then confidence rated their answers to questions on its content. A condition (the Individual–Pair condition) where individual effort preceded pair collaboration showed better calibration compared with a condition (the Simple Pair condition) where no individual effort took place. Furthermore, within the Individual–Pair condition, better calibration, and lower overconfidence, were found in the pair phase compared with the individual phase. The eyewitnesses in the Individual–Pair condition made more realistic judgements of the total number of questions answered correctly. In a control experiment no effect on realism in confidence was found when individuals performed the same task twice. The improved realism in the Individual–Pair condition may partly be explained in terms of the increased accuracy and lowered confidence found for such items where the pair members’ had given different answers in the individual phase, and by a risky shift effect for such items where they had given the same answer.