Space‐planted populations derived from ‘Holt’ and ‘Oto’ indiangrass, Sorghastrura nutans (L.) Nash, were used to obtain heritability estimates for forage yield, in vitro dry matter digestibility (IVDMD), crude protein, and heading date and to determine their genotypic correlations. Heritability estimates were determined by variance component analyses and by parent‐progeny regression. Average narrow sense heritability estimates for the two populations were 0.43, 0.42, and 0.50, for forage yield, IVDMD, and protein, respectively. Narrow sense heritability estimates for heading date were 0.90 or larger. Genotypic correlations of yield and IVDMD were negative for the Holt population but were positive, although low, for the Oto population in 1976. Protein and IVDMD had positive genotypic correlations for both populations. Heading date was positively correlated with yield but was negatively correlated with IVDMD and protein.