A mechanically agitated laboratory continuous crystallization system of capacity 1 litre has been developed with special application to the precipitation of aluminium hydroxide. It consists of continuous liquor and seed feeding arrangements and semi-continuous product evacuation as recommended by Randolph and Larson. A study of the particle dynamics and the solid and liquid residence time distributions has shown that the set-up represents a normal continuous mixed suspension mixed product removal (CMSMPR) system. It was found that the liquor concentration achieved steady state after 2 to 3 residence times and the slurry density, after 4 residence times; however, it was difficult to attain an absolute steady state for the solid CSD.