This paper investigates the effects of the cutting tool edge radius on the cutting forces and stability lobes in micro-milling. The investigation is conducted based on recently developed models for prediction of micro-milling cutting forces and stability lobes. The developed models consider the nonlinearities of the micro-milling process, such as nonlinear cutting forces due to cutting velocity dependencies, edge radius effect and run-out presence. A number of finite element analyses (FEA) are performed to obtain the cutting forces in orthogonal cutting which are used for determining the micro-milling cutting forces. The chip morphology obtained for different tool edge radii using FEA is presented. It is observed that at large tool edge radii the influence of the ploughing effect become more significant factor on the chip morphology. The results related to micro-milling cutting forces and stability lobes show that by enlarging the tool edge radius the micro-milling cutting forces increase while the stability limits decrease.