The chemical diffusion coefficients of single crystals of cadmium tellurideDCdTewere determined as a function of temperature and composition using high‐temperature electrical conductivity measurements. In the temperature range 550° to 800°C,DCdTecan be approximated by 4 exp[− (1.15±0.1) eV/kT] and is nearly independent of cadmium partial pressurepCd, forpCdextending over two decades from the cadmium‐rich liquidus. The measured and calculated values ofDCdTeare in good agreement, and the results favor an interstitial mechanism for cadmium self‐diffusion.