Plasma insulin-like growth factor-I (IGF-I) concentrations measured in young cattle from 2 beef cattle genetic experiments were used to investigate its genetic relationship with feed intake and several measures of feed efficiency. IGF-I was heritable and the genetic correlations across datasets suggested a moderate positive relationship with both residual feed intake and feed conversion ratio. Genetic correlations with growth rate tended to indicate a slightly negative relationship. Estimates of correlations with feed intake and mid-test weight were inconsistent between datasets, but in general were small. These estimates, although from very small numbers of records, suggested that further research on IGF-I should be conducted. The potential benefits of using IGF-I to indirectly select for feed efficiency traits are large.