The impact and spreading of liquid droplets on a smooth solid substrate continues to receive much attention in various disciplines, due to its importance for a wide range of applications in nature and industry. Examples include ink-jet printing, rain drop dynamics, fuel combustion, spray cooling, coating, and many others. In our group we study the dynamics of impact and spreading of Newtonian and non-Newtonian droplets on solid surfaces with different wetting properties. In particular, we are interested in understanding the effect of polymer additives on the behaviour of droplets during the spreading. Experimental investigations and mathematical modeling are used to describe the physics of interface deformation and moving contact line dynamics.