Purpose: Environmental factors such as bathing may play a role in atopic dermatitis (AD) development. This analysis utilized data from the Community Assessment of Skin Care, Allergies, and Eczema (CASCADE) Trial (NCT03409367), a randomized controlled trial of emollient therapy for AD prevention in the general population, to estimate bathing frequency and associated factors within the first 9 weeks of life., Methods: Data were collected from 909 parent/newborn dyads recruited from 25 pediatric and family medicine clinics from the Meta-network Learning and Research Center (Meta-LARC) practice-based research network (PBRN) consortium in Oregon, North Carolina, Colorado, and Wisconsin for the CASCADE trial. Ordinal logistic regression was used to conduct a cross-sectional analysis of the association between bathing frequency (measured in baths per week) and demographic, medical, and lifestyle information about the infant, their family, and their household. Variables were selected using a backwards-stepwise method and estimates from the reduced model are reported in the text., Results: Moisturizer use (OR = 2.03, 95% CI: 1.54-2.68), Hispanic or Latino ethnicity (OR = 1.97, 95% CI: 1.42-2.72), a parental education level lower than a 4-year college degree (OR = 2.48, 95% CI: 1.70-3.62), living in North Carolina or Wisconsin (compared to Oregon; OR = 2.12 and 1.47, 95% CI: 1.53-2.93 and 1.04-2.08, respectively), and increasing child age (in days; OR = 1.02, 95% CI: 1.01-1.02) were significantly associated with more frequent bathing, while pet ownership (OR = 0.67, 95% CI: 0.52-0.87) was significantly associated with less frequent bathing., Conclusions: We found significant ethnic, geographic, and socioeconomic variation in bathing frequency before 9 weeks of age that may be of relevance to AD prevention studies., (© 2023 Wiley Periodicals LLC.)