A recently developed capillary method has been employed to study tracer self-diffusion in liquid Na (102 to 284°C) and K (97 to 284°C). The results may be expressed byD=D0exp(-Q/RT), where 103DoNa= 0.86 (+0.09, −0.08) (cm2/sec),QNa=2.22 ±0.08 (kcal/mole), 103DOK= 0.76 (+0.06, −0.05), andQK= 2.02 ± 0.07. The reexamination of electrotransport data for Rb (60 to 230°C) yielded the self-diffusion data 103DORb= 0.66 (+0.11, −0.09) andQRb= 1.98 ± 0.16. For liquid Li, the results of two investigations (195 to 440°C) have been combined, yielding 103DOL1= 1.44 (+ 0.07, −0.06) andQL1= 2.87 ± 0.07