Axial wall temperature distribution of R410a and water filled thermosyphons at various fill ratios and inclination angles are experimentally determined. Power was supplied using resistance band heaters. A water cooled jacket surrounded the condenser section. Power input ranged from 100 – 830 W. Fill ratios of 0.93, 0.66, 0.4 and 0.25 were employed for the R410a pipe and 1.00, 0.75, 0.50 and 0.25 for the water filled pipe. Inclination angles were set at 30 o , 50 o , 70 o and 90 o . The results showed that the evaporator wall temperature was not uniform especially at high power input, low fill ratios and large inclinations.