We present the first experimental measurements of surfactant curviline
ar diffusion in giant wormlike micelles. The surfactant diffusion was
monitored by pulsed field gradient NMR for various observation times t
ranging from 0.020 to 1.5 s. The surfactant mean-square displacement
was found to scale as t(1/2). A model of lateral diffusion along worml
ike micellar aggregates with Gaussian statistics is found to describe
the echo attenuation well. This type of diffusion is analogous to poly
mer segment diffusion in the tube-reptation model.