The soluble fiber (1→3),(1→4)-β-D-glucan has been identified as an active component of oat (Avena sativa L.) that lowers serum cholesterol, reduces the risk of heart disease and colon cancer, and alleviates the symptoms of diabetes. Those beneficial effects may be caused by the ability of β-glucan to generate viscosity in the digestive system. The objective of this study was to estimate the genetic components of variance for β-glucan content and oat slurry viscosity in a population derived from the cross of high β-glucan with elite agronomic oat lines. Twelve high β-glucan inbred lines were crossed with 12 inbred lines with good agronomic performance. The F3:4 generation was evaluated in 2005 at two Iowa locations. The range in β-glucan content was 37.1 g kg−1 to 73.5 g kg−1 A positive correlation (r 2 = 0.38) was found between β-glucan content and log-transformed viscosity. High β-glucan lines tended to have low grain yield and biomass. Significant variation among families and among lines within families were observable for most traits, suggesting selection for β-glucan content, viscosity, and viscosity deviation should be feasible.