The Devils River minnow (Dionda diaboli) coexists with at least 2 congeners and several other cyprinids throughout its range in southern Texas and northern Mexico. Larval and juvenile descriptions are needed to monitor D. diaboli larvae and juveniles as part of recovery efforts for this species of conservation concern. The purpose of this study was to describe and quantify characteristics of early life stages of D. diaboli from hatching to 128 d post hatch to facilitate larval and juvenile identification. Descriptive characters include mid-lateral band of melanophores by Day 8 (>5.1 mm SL; >5.4 mm TL), mid-lateral band of melanophores separate from a rounded caudal spot and lateral snout-to-eye melanophores by Day 16 (>5.8 mm SL; >6.3 mm TL), initial coiling of intestine by Day 32 (>6.2 mm SL; >7.2 mm TL), wedge-shaped caudal spot by Day 64 (>8.7 mm SL; >10.0 mm TL), and melanophores around scale margins and mid-lateral double dashes along lateral line by Day 128 (>13.5 mm SL; >16.0 mm TL). However, reliable separation among sympatric Dionda might not be possible until larvae and juveniles of congeners are described.