Stimulation of lens fiber cytoskeletal phosphorylation by adrenergic drugs is described. The effect of isoproterenol on phosphorylation of the 47Kd beaded filament protein is dose-dependent, detectable as soon as one minute after treatment and blocked by propranolol. Epinephrine increases the phosphorylation of both 47Kd and the intermediate filament protein, vimentin. 47Kd phosphorylation is also increased by norepinephrine, dibutyryl-cAMP or forskolin. The results indicate that lens fiber cytoskeletal phosphorylation is regulated, at least in part, via a beta-adrenergic receptor coupled to cyclic AMP production.