The first quantum correction to a time correlation function is obtained by expanding the quantum-mechanical correlation function in powers of Planck's constant. Quantum corrections to time correlation functions are of interest because they may be used to obtain quantum corrections to transport properties. An application of the formalism to nuclear spin-lattice relaxation is included. A formal expression is obtained for the first quantum correction to the lattice time correlation functions. The effect of this correction on the relaxation time is indicated. The possibility of using the first quantum correction to calculate isotope effects on transport properties is discussed.