ABSTRACT Workaholism is a work-related addiction, and the study of its antecedents has a strong individual and social impact. Several studies reported high trait perfectionism in individuals exhibiting workaholism. Although the relationship between perfectionism and workaholism is quite consistent in the literature, it is not yet clear which biological underlying mechanisms might explain this relationship. From a chronopsychological perspective, it has been widely demonstrated that evening-type individuals are more prone to develop addictive behaviour. In the present study, we investigated, for the first time, the role of circadian typology in the relationship between perfectionistic concerns and workaholism. A group of Italian workers (N = 369; 60.70% females; mean age of 38.60 years) took part in a survey. Participants filled in the Bergen Work Addiction Scale (for workaholism), the Morningness-Eveningness Questionnaire (for circadian typology), and the Short Almost-Perfect Scale (for perfectionism). In addition to age, we controlled for workload using the Job Content Questionnaire. Beyond the confirmation of the relationship between perfectionism and workaholism, we found that in high perfectionistic individuals, evening-types reported higher score in Bergen Work Addiction Scale. Based on these findings, limitations and suggestions for future research are discussed.