Surveys conducted over the last few years on representative samples in the US and Germany suggest that the percentage of parents who regret having children is approximately 17–8%. In none of these studies did the researchers attempt a detailed examination of this group of parents from the perspective of their psychological functioning. In the present article, two studies based on large, national samples (N = 1175 and N = 1280), one of which was a representative sample of young Poles, are presented. The results obtained show that the percentage of parents who regret parenthood is higher in Poland than in the US or Germany, and that parents who regret having children are characterized by a higher level of adverse childhood experiences, have poorer psychological and somatic health, are more vulnerable to social evaluation, and experience strong parental identity crisis and parental burnout. Regretting parenthood also turns out to be associated with the parent’s financial situation and marital status, and with having children with special needs. The results indicate that regretting becoming a parent is an important social and psychological issue that should become an object of interest for researchers from various disciplines and for social policy authorities.