The effects of 1-wk medication with two beta-adrenoceptor antagonists on unstimulated whole saliva flow rate and protein composition were evaluated in 11 healthy young men in a randomized, double-blind, placebo-controlled, cross-over study. Unstimulated whole saliva was collected before each treatment period and then again after 7 days. The saliva was assessed for flow rate, total protein, and hexosamine and sialic acid concentrations and for amylase activity. No significant effect on saliva secretion rate was found. A statistically significant reduction of salivary total proteins was registered during atenolol medication. The amylase activity decreased significantly during treatment with both atenolol and propranolol. Significant changes of the calculated ratios of sialic acid/hexosamine and hexosamine/total protein indicated an alteration in glandular protein synthesis after atenolol treatment.