This study profiles workers’ use of informal training to upgrade their skills in Quebec, drawing on data from the Skills Self-Assessment module (LMSI) of the four most recent waves of the Longitudinal and International Study of Adults (LISA): 2014, 2016, 2018 and 2020. We examine the types of activities employees use to improve their skills, distinguishing between structured formal training and informal training; the activities perceived as having the greatest effect on skill levels; and the characteristics of the employees who engage in them, with particular attention to differences between Quebec, Ontario and the rest of Canada. Our results show that, among workers who reported an improvement in their skills, informal training is used far more often than formal training, with participation rates above 90% in all three regions. However, Quebec workers consistently make less use of it than their counterparts in Ontario and the rest of Canada.