The causes of acute malnutrition—or “wasting”—are complex, and a better understanding of the underlying drivers is necessary in order to design effective interventions. Water, sanitation, and hygiene (WASH) practices may play a fundamental role in acute malnutrition, but more research is needed to confirm this relationship. We investigated the association between WASH practices and acute malnutrition among children 6 to 59 months of age in rural Ethiopia, making use of the Ethiopian Demographic and Health Survey. Descriptive statistics were used to assess the WASH status of all rural children. Bivariate logistic regression analyses were performed to assess associations between nutritional status and WASH. Multivariate logistic regression analyses were used to adjust for confounders. A total of 7,209 children were included in the analysis, of which 867 (12.0%) were acutely malnourished. Proper toilet facilities (AOR = 0.63, 95% CI [0.46, 0.86]) and a water source close to home (AOR = 0.71, 95% CI [0.61, 0.83]) were associated with a lower prevalence of wasting. A safe water source for drinking (COR = 1.03, 95% CI [0.89, 1.19]) and a safe disposal of the child's stool (AOR = 0.97, 95% CI [0.84, 1.13]) were not significantly associated with acute malnutrition. These results suggest that WASH practices are related to acute malnutrition. Future studies—in particular intervention studies—should investigate whether improving WASH practices is effective in reducing malnutrition in infants and young children.