A numerical study of droplet deformation in a high-pressure homogeniser is presented. This work is an attempt to identify flow criteria responsible for droplet break-up in a homogeniser used to produce dispersions for the manufacture of photographic paper. The main goal of this study is to recommend changes to homogeniser flow & geometry, operating conditions or fluid properties that will enhance droplet break-up. Laminar elongation, turbulent stresses within the orifice and downstream turbulence and cavitation have been suggested as possible mechanisms within the homogeniser for droplet rupture. Results for simulations, using a combination of homogeniser and droplet scale computation indicate that droplets are unaffected by local extensional flow or turbulent fluctuations and that other mechanisms must be responsible for droplet break-up.