Premature ejaculation is the most prevalent form of male sexual dysfunction, but its cause has not been well established. Recent studies have indicated that in men with premature ejaculation, penile sensitivity is increased. To investigate whether penile hypersensitivity is a cause of premature ejaculation, we prospectively evaluated the penile sensitivity of 18 patients with a lifelong history of premature ejaculation from the first coital experience and 15 controls, both in the flaccid and erect state. We used an SMV-5 vibrometer (Suzuki-Matsuoka, Teknologue, Tokyo, Japan), which automatically controls stimulatory strength; its precision and reproducibility are thus higher than analogue-type biothesiometers. At the styloid process of the ulna and medial maleolus of the tibia, there was no significant statistical difference in vibratory threshold between the two groups (P > 0.05). Also we did not find significant statistical differences in sensitivity of the glans penis, dorsum of the penile shaft, or frenulum of the penis between the two groups, in either the flaccid or erect state (P > 0.05). According to our results, penile hypersensitivity, as measured by an SMV-5 vibrometer, does not appear to be a major factor contributing to premature ejaculation.