This study investigates productive efficiency for a sample of Missouri crop-only (specialized) and integrated crop-livestock (diversified) farms using a cost frontier approach. Results suggest that significant cost inefficiency exists among sample farms. Lower cost efficiency in both types of farms was attributed to improper scale of operations and mis-allocation of inputs. On average, diversified farms were as technically and scale efficient as specialized farms. Lower allocative efficiency diluted gains in technical efficiency and resulted in greater cost inefficiency for diversified farms than for specialized farms. Technical efficiency was independent of farm size, whereas allocative, scale, and scope efficiencies were not.