Objective <p>This study aimed to develop and evaluate the psychometric properties of a diarrhea management scale for mothers with children aged 0–24 months.</p> Methods <p>This methodological study was conducted between February and June 2023 with 449 mothers in the pediatric emergency department of a training and research hospital in Istanbul. Data were collected using a sociodemographic data form and the Diarrhea Management Scale for Mothers (DiMaM). The scale’s validity and reliability were analyzed using the Kaiser–Meyer–Olkin coefficient, Bartlett’s Test of Sphericity, Cronbach’s alpha reliability coefficient, fit indices, independent samples t-test, test–retest analysis, mean item scores of the 27% lower and upper groups, and item-total correlation statistics.</p> Results <p>Factor analysis revealed five factors explaining 71.466% of the total variance. The Cronbach’s alpha coefficient was 0.887 for the overall scale, 0.913 for the intestinal and stool monitoring subscale, 0.762 for the symptom monitoring subscale, 0.735 for the therapeutic interventions subscale, 0.683 for the hygiene and responsibility subscale, and 0.743 for the nutrition and fluid supplementation subscale. Confirmatory factor analysis indicated acceptable fit indices for the scale. Standardized factor loadings ranged from 0.549 to 0.930, and Intraclass Correlation Coefficient values ranged from 0.886 to 0.916.</p> Conclusions for Practice <p>DiMaM was determined to be a valid and reliable tool for assessing diarrhea management in the home environment for mothers with children aged 0–24 months.</p>