India is one of the leading producers of coconut in the world. Dehusking is the primary post-harvest operation done in coconuts to remove the husk from the nut and it is a laborious process, which adds to the cost of production in the coconut processing industry. A study was undertaken to develop a coconut dehusking machine for easy and effective removal of husk from coconut without causing much damage to the nut. For the development of coconut dehusker, various required engineering properties of matured coconuts viz., average dimensions such as length of 200 mm, diameter of 145 mm, husk thickness of 33 mm at pedicel end, 22 mm at both centre and apex ends were determined. The average moisture content of green coconuts was observed as 45.6 % (w.b.) and the shell diameter of the dehusked green coconuts as 89 mm. The maximum husk penetrating force for matured green and dry coconuts were observed as 166 N and 196 N, respectively at a thickness of 33 mm. also, the maximum husk separating force was determined as 430 N and 520 N for green and dry coconuts respectively. A coconut dehusker was developed based on the principle of exerting shear force by the rotating roller blades to cause tearing effect over the husk surface. The effective dehusking was achieved when the roller speed of 18 rpm was found to be suitable for both green and dry coconuts of various sizes with the maximum dehusking efficiency of 97%.