Investigation of the effects of body position and clothing on the temperature of the scrotum has given discordant results. The aim of the present study was to evaluate these effects in 13 fertile male volunteers in successive positions each held for 15 minutes, either Supine, Standing, Seated with legs apart, and Seated with legs crossed (n 5 8) or Standing, Seated with legs crossed, and Standing (n 5 5), at first naked and then clothed. The Standing naked position was that in which scrotal temperature reached the lowest point. Clothing increased the scrotal temperature compared with the naked state, whatever the position. The Seated with legs crossed position had specific characteristics: in the naked state, it was thermogenic and increased scrotal temperature as much as clothing in the Supine or Standing positions; in the clothed state, the increase in temperature was less than expected, which could indicate that local mechanisms are involved. Moreover, the Seated with legs crossed position had a persisting effect on scrotal temperature in the next position. These results have both pathophysiological and epidemiological implications.