Decision-making is a complex cognitive process which consists of choosing one option among several alternatives. In humans, this process is featured in the Iowa gambling task (IGT), a decision-making task that mimics real life situations by reproducing uncertain conditions based on probabilistic rewards or penalties (see Background). Several authors wanted to adapt the IGT in rodents with subtle differences in protocols that match various aspects of the human task. Here we propose, for the first time in mice, a protocol that contains the most important characteristics of the IGT: 4 different options, choices based on 4 ambiguous outcomes with immediate and long term rewards, a total of 100 trials, no learning of the contingency before the task, and presence of both a certain reward and a probable penalty. During this task, mice have to choose between options more or less advantageous in the short and long term by developing a decision-making strategy that differs between individuals. Therefore, the strength of this protocol is that it is one of the first to enable the study of decision-making in a complex situation, and demonstrates inter-individual differences regarding decision-making strategies in mice.