PURPOSE: To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. MATERIALS AND METHODS: For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR III was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of handheld dental X-ray unit were 70kVp, 3mA , 0.1 second, and of fixed X-ray unit 70kVp, 8mA, 0.45 second. RESULTS: The mean dose at the hand level when human skull DXTTR III was exposed with portable X-ray unit 6.39 micronGy, and the mean dose with fixed X-ray unit 3.03 micronGy (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was 2.97 micronGy and with fixed X-ray unit the mean dose was 0.68 micronGy (p<0.01). CONCLUSIONS: The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography.