1. The effect of propranolol on the clenbuterol-induced protein anabolism in innervated and denervated soleus and plantaris muscles of the rat was studied. 2. The response to the beta-agonist, clenbuterol, in both innervated and denervated muscles, was not significantly inhibited by the beta-antagonist, propranolol. 3. The results provide further evidence to suggest that the action of clenbuterol on skeletal muscle protein accretion may not be directly mediated by beta-adrenoceptors.