Undernutrition in children is a challenging problem in developing countries, including Ethiopia. Stunting is the most prevalent form of undernutrition. The majority of studies on childhood stunting and its associated factors focused on children, maternal and socioeconomic components. However, a few studies reported poor WaSH status and antibiotic exposure as environmental risk factors for child stunting, and the case of socio-demographic factors also lacks consistency. Concerning this, there is a lack of information in Ethiopia. Therefore, the present study assessed the association of socio-demographic, WaSH, and antibiotic exposure with stunting among under-five children. A cross-sectional study was conducted involving 340 mother–child pairs. Anthropometric data were collected using standard and calibrated height and weight scales. For factorial data, an interviewer-guided standard questionnaire was used. Logistic regression analyses were used to identify factors determining childhood stunting. In the present study, the prevalence of stunting, underweight and wasting was 14⋅7 % (95 % CI 10⋅9, 18⋅5), 4⋅4 % (95 % CI 2⋅4, 6⋅8) and 2⋅1 % (95 % CI 0⋅6, 3⋅5), respectively. Low dietary diversity, being born from a mother with an education level of secondary school, and belonging to a female-headed household were positively associated (P < 0⋅05) with stunting. The prevalence of overall undernutrition was lower (21⋅2 %) in the study area. Stunting was significantly associated with dietary diversity, maternal educational level and sex of households head. The government policy should focus on enhancing the dietary diversity of households, and encouraging women's education.