Unpasteurized (raw) milk can be purchased in 39 U.S. states, with direct consumer purchase for human consumption permitted in 29 of those 39 states. Raw milk (n=21; cow, 14; goat, 7) was purchased in 12 states, and Coxiella burnetii, the agent of Q fever, was detected in 9 of 21 (42.9%) samples tested by polymerase chain reaction. Viability of the pathogen was demonstrated by isolation of the agent in tissue culture. The demonstration of viable C. burnetii in commercially available raw milk poses a potential public health risk.