The self‐diffusion of antimony has been measured in single crystals with the tracer124Sb. The least‐squares fit to the data gives in the direction of the trigonal axisQ‖=47.1±1.2 kcal/mole and ln(D0in cm2/sec)=3.1±0.7, and in the plane perpendicular to the trigonal axisQ‖=44.4±4.9 kcal/mole and ln(D0in cm2/sec)=2.81±2.8. The standard sectioning technique was used except that the very friable nature of the semimetal complicated the procedure at practically every step of the operation. The greatest source for the inaccuracy arose from the ``tails'' on the deep penetration side, noticable forD‖and strongly prominent forD‖. Correlation considerations in the Sb lattice are considered in detail in the Appendix.