Cycling is one of the most sustainable transport modes available and it is widely promoted inmany urban areas. The health benefits from cycling has shown to be substantial, includingdecreased risks of diseases related to overweight and enhancing brain capacity. However, inurban areas cyclists can temporaly be exposed to high levels of air pollution, resulting inhealth risks as opposed to health benefits. The objective of this thesis is to develop a rasterbased test model in GIS that estimates theinhaled dose of air pollution for cyclists based on relative particle concentration in differenttransportation micro-environments. The method used is a least-cost path approach,calculating three different routes; shortest, fastest and least dose for four different trips withinSödermalm, Stockholm. The results show that the inhaled particle dose can be greatly reduced, 39% - 58% for three ofthe routes, by choosing the least dose route. One of the most interesting findings is thesubstantial increase of dose when high levels of particles are combined with uphill cycling. The conclusion for the thesis is that a raster-GIS model can be very useful for estimating doseof different air pollution particles and chemicals along cycling routes. For this purpose thetest model could be applied with no or little additional development, while with furtherdevelopment it might be possible to develope a cycle route planner for public use.