First order reactions in laminar Newtonion and non-Newtonion fluids in coiled tubes have been analyzed for high range of Dean numbers (N-Dl < 250). Process parameters which govern the secondary flow and the reaction parameter on the performance of coiled tube chemical reactor are systematically examined. It is interesting to observe that the phenomenon of covective diffusion with reaction in coiled tube can be simulated. Numerical calculations show the effect of process parameter modelling the rection parameter (alpha), dimensionless axial distance and power law index (n). The performance of the coiled tube reactor is compared with plug flow and laminar flow reactors.