Non-alcoholic fatty liver disease (NAFLD) is the main liver disease worldwide, and its prevalence in children and adolescents has been increasing in the last years. It has been demonstrated that parental exposure to different conditions, both preconceptionally and during pregnancy, can lead to fetal programming of several metabolic diseases, including NAFLD. In this article, we review some these maternal and paternal conditions that may be involved in early-life programing of adult NAFLD. First, we describe the maternal nutritional factors that have been suggested to increase the risk of NAFLD in the offspring, such as an obesogenic diet, overweight/obesity, and altered lipogenesis. Secondly, we review the association of certain vitamin supplementation and the use of some drugs during pregnancy, for instance glucocorticoids, with a higher risk of NAFLD. Furthermore, we discuss the evidence showing that maternal-fetal pathologies, including gestational diabetes mellitus (GDM), insulin resistance (IR), and intrauterine growth restriction (IUGR), as well as the exposure to environmental contaminants, and the impact of microbiome changes, are important factors in early-life programming of NAFLD. Finally, we review how paternal pre-conceptional conditions, such as exercise and diet (particularly obesogenic diets), may impact fetal growth and liver function. Altogether, the presented evidence supports the hypothesis that both in utero exposure and parental conditions may influence fetal outcomes, including the development of NAFLD in early-life and adulthood. The study of these conditions is crucial to better understand the diverse mechanisms involved in NAFLD, as well as for defining new preventive strategies for this disease.