The purpose of this investigation was to determine if there was any relationship between dietary carnitine intake and the concentrations of carnitine in skeletal muscle and blood plasma in healthy adult men and women. Subjects (14 men, 14 women, fasted 8 h) reported to the Biodynamics Laboratory where they completed a 24-h diet recall questionnaire. Resting muscle biopsy (vastus lateralis) and blood plasma samples were taken and assayed for free, short-chain, and long-chain acyl carnitine concentrations. Dietary carnitine intake was estimated from data on concentrations in food. There was no significant relationship between either protein or carnitine intake with skeletal muscle carnitine concentrations. There was a significant relationship between both dietary carnitine (r = 0.50) and protein (r = 0.48) intake with blood plasma total acid soluble carnitine concentrations (p less than 0.01) in all subjects.