Fasting salivary free and total PSA levels are not effected by high serum levels of prostatic origin. Although there was a significant difference between mean serum and salivary levels of free and total PSA in each group, the f/t ratio of saliva was very close to the serum ratio of normal subjects. Determination of free and total PSA in saliva to improve and simplify the differentiation between prostate cancer and BPH is not suitable for use as alternative measurement of serum