In this work, the relation between heat transfer performance and interruption of microchannels was investigated. Experiments were conducted on uninterrupted and interrupted aluminium channel heat sinks of different channel widths. Two different types of interrupted channels were tested: channels having single interruption and 7 interruptions. Distilled water was used to remove a constant heat load of 40 W in the volumetric flow rate range of 0.5-1.1 lpm. The interruption of channels improved the thermal performance over the uninterrupted counterparts up to 20 % in average Nusselt number, for 600 micron-wide channels. The improvement of average Nusselt number between the single interrupted and multi interrupted channels reached a maximum value of 56 % for 500 micron-wide channels. This improvement did not cause a high pressure drop penalty. In the tests, maximum temperature difference between the inlet of the fluid and the base of the channel was observed as 32.8 degrees C.