BACKGROUND: Balanced energy protein (BEP) supplementation in pregnant women in low-and middle-income countries may reduce the risk of stillbirth and low birth weight. OBJECTIVES: The objective of this study was to assess the adherence to and acceptability of a corn-soy blend (CSB) BEP product among pregnant women in rural Ethiopia. METHODS: This formative study was conducted from October to November 2018 among pregnant women in the rural Amhara region of Ethiopia prior to initiation of a clinical effectiveness study (ISRCTN: 15116516). We assessed adherence and acceptability of a micronutrient-fortified CSB BEP supplement among 40 pregnant women during a 4-wk utilization period. Acceptability was assessed using a 7-point Likert-style scale about the hedonic characteristics of the BEP product at 2 wk and 4 wk. Adherence was assessed by weekly monitoring and empty sachet counts for BEP consumption over 4 wk. RESULTS: Adherence to the BEP was, on average, 89% over the month-long pilot. The BEP product was rated favorably (mean Likert score >6 of 7) for the following domains: color, taste, odor, and likeability at mid and endpoints. Women found the product convenient to eat [mean (standard deviation [SD] = 5.9 (1.0))] and filling (mean (SD) = 6.1 (1.5) out of 7). Scores on acceptability and perception of the product remained stable throughout the duration of use. A majority of women (63%) reported consuming the BEP as a snack to supplement meals and splitting the serving over 2 or more sessions (68%). A quarter of respondents reported sharing the supplement with family members. CONCLUSIONS: Adherence and acceptability of the CSB BEP product were high among this population in rural Amhara, Ethiopia. This formative data was important to select the final product and shape the counseling and delivery of BEP in the parent study.