This study examined sustained competitive advantage for a sample of Kansas farms. Whole-farm data for 224 farms with continuous data from 1982-2001 were used. Overall efficiency was computed for each farm and year. Sixty farms exhibited a sustained competitive advantage. Seventy-six farms exhibited a sustained competitive disadvantage. Farms with a competitive advantage were relatively larger, received more of their gross farm income from dairy and swine production, had significantly lower expense ratios, and had significantly higher profit margins.