Fractures act as a highly permeable conduit for flow in naturally fractured reservoir. Geo-chemical reactions inside fractures may lead to partial or complete filling of pore spaces inside fractures over time. This reduction in fracture aperture directly affects its capability to transport fluid. The current study presents a 1-D mathematical model to simulate the geochemical filling of natural fractures. The fracture walls have been represented by simple mathematical functions to reflect variable aperture of natural fractures. Mass transfer through convection/diffusion and mineral precipitation due to precipitation/dissolution reaction were solved as a simplified mathematical representation of the actual processes. Precipitation reaction is coupled with mass transport by the fluid to ensure mass conservation of reacting components. For simplification, calcite precipitation in fracture has been modelled. The effect of pressure drop, diffusion constant, type of fracture aperture profile on evolution of fracture aperture was simulated in this study. Comparison is made between increasing, decreasing and constant fracture profiles to understand their effect on fracture evolution. This study aims to present a methodology to model variable fractures and study its effect on deposition inside the fracture. The model shows that the simple parallel model over predicts the precipitation that occurs in a fracture. © 2016 Indian Society for Hydraulics.