Basal pulsatile secretion of luteinizing hormone (LH) was studied in 8 healthy adult men and analyzed by mathematical and statistical techniques. LH pulses previously defined by semiquantitative criteria resisted the data-smoothing techniques employed. LH values were shown to have normal distribution in normal men. No correlation was found between mean LH and testosterone levels for the same individual. On the basis of analysis of variance it was shown that the individual variability and not the collection time is important in determining each isolated LH value. The LH levels were located within a particular channel for each individual for each collection time.