Experimental investigations of the flows inside helically coiled pipe are difficult and may also be expensive, particularly for small diameters. Computational fluid dynamics (CFD) packages, which can easily construct the geometry and change the dimensions with 100% of accuracy, provide an alternative solution for the experimental difficulties and uncertainties. Therefore, a computational fluid dynamics (CFD) study was conducted to analyse the flow structure and the effect of varying the coil pitch on the coil friction factor and wall shear stress, through utilising different models' configurations. Three coils were tested, all of them sharing the same pipe and coil diameter: 0.005m and 0.04m respectively. Pitch variations began with 0.01, 0.05, 0.25 m for the first, second and third model respectively. In this study, the pressure drop was analysed, and the effects of this reduction on wall shear stress and coil friction factor were also examined using incompressible viscous laminar flow to elucidate the effect of varying coil pitch on the friction factor and wall shear stress. The results were validated by Ito's equation for the laminar flow and compared with the Hagen-Poiseuille resistance formula for a straight pipe.