PURPOSE:To determine the prevalence and sociodemographic and hospitalization history of genetic conditions in a sample of inpatients in a pediatric hospital in 2017, and to compare results with unpublished studies from 1985, 1995, and 2007. METHODS:Two weeks of admissions were classified according to a pre-existing categorization, based on genetic etiology, encompassing chromosomal and monogenic conditions, multifactorial (MF) conditions, and no known genetic cause. RESULTS:In 2017, 299 (16%) patients had chromosomal or monogenic conditions, 6-7% more than 2007 and 1995, but similar to 1985. Autosomal dominant (AD) conditions increased from <2% previously to 6% in 2017 (p < 0.001). MF conditions comprised the majority throughout, increasing from 45% to 54%. Age at admission was highest in autosomal recessive (AR) and X-linked categories in 1995, 2007, and 2017, reflected in their high number of previous admissions, while the AD, MF, and nongenetic categories were the youngest with similar lengths of stay and previous admissions. CONCLUSION:Conditions with a genetic contribution account for over half of pediatric inpatients. Since 1985, there have been many changes in age at admission and length of stay, but it is the increasing prevalence of AR, AD, and MF conditions that is important when considering future service provision.