This paper concerns the problem of disperse liquid - liquid systems behaviour. The research was carried out using the classical emulsifying method with mechanical stirrer and ultrasonic energy. Droplet size of disperse phase was measured photographically and using a camcorder. The examined issues were the influence of disperse phase hold-up, stirrer rate and ultrasonic waves on water/alcohols mixture and water/lactamic oil/trichloroethylene systems. The diversity of breakage and coalescence frequencies of disperse phase droplets was estimated.