Particle transport has been an active area of research for many years. Despite many excellent experimental and modeling studies contributing to the fundamental understanding of particle transport, the effect of viscosity is still not well-understood. There are limited experimental studies addressing the effect of viscosity on particle transport. Even among those limited studies, contradictory conclusions have been reported in the literature. A review of the single-phase proposed models also reveals that fluid viscosity has not been well addressed in the models as well. The main focus of this study is to investigate the effect of viscosity on particle transport in laminar and turbulent flows. Experiments were performed using a 0.05 m diameter pipe. Comparisons of the obtained data with previously reported data in the literature show similar characteristics. The current study finds that liquid flow regime in the pipe plays an important role on how viscosity affects the particle transport phenomenon. Discussions presented in this work to explain the obtained experimental data shed light on this less addressed physical parameter.