Evidence-based recommendations for optimal showering/bathing practices are lacking for atopic dermatitis (AD) patients. To determine longitudinal associations between showering/bathing practices and AD severity in AD patients. A prospective single-center dermatology practice-based study was performed. Shower/bath frequency and duration, and frequency of applying moisturizers after showering/bathing were evaluated. AD severity was assessed using objective component of Scoring Atopic Dermatitis (o-SCORAD), SCORAD-itch, Eczema Area and Severity Index (EASI), Patient-Oriented Eczema Measure (POEM), and Dermatology Life Quality Index (DLQI). Repeated-measures regression models examined associations of showering/bathing and moisturizing practices with change in AD severity measures over time. Showering/bathing more than daily versus once daily was associated with higher SCORAD-itch, o-SCORAD, EASI, POEM, and DLQI scores; less than daily versus once daily showering/bathing was not associated with any outcomes. Consistent and even inconsistent application of moisturizer after showering/bathing was associated with lower o-SCORAD, EASI, and POEM scores. Showering/bathing duration was not associated with AD outcomes. Severe SCORAD-sleep, o-SCORAD, EASI, and POEM were associated with less adherence to all showering/bathing recommendations. Showering/bathing daily or less frequently and applying moisturizer postshower/bath were associated with lower AD severity; showering/bathing duration was not. Recommendations concerning shower durations may not be necessary when counseling AD patients.