Formation damage due to fines migration is a major factor which reduces reservoir productivity. It is, therefore, essential to know the critical condition at which particles migrate in pores and subsequently plug the channels. This paper describes the application of fractal analysis for predicting critical conditions for particles to deposit in pores. The experimental data were obtained by injecting suspensions (bentonite) through a fabricated glass micro capillary (100 μm ID) at a controlled flow rate and at the same time continuously monitoring the pressure build-up across the capillary. Based on the experimental data and theoretical analysis, a criterion for predicting the critical condition for fines migration in pores is proposed.