Abstract A direct colorimetric method was described for the rapid, sensitive and accurate determination of dibucaine, lidocaine, bupivacaine, procaine and tetracaine in pharmaceutical preparations. The method involves the use of haematoxylin reagent in the presence of boric acid to give a reddish-violet chromogen (λmax = 555 nm). Beer's law was obeyed in the range from 2–60 μg/ml. No interference was observed from the commonly present additives or agents in pharmaceutical formulations.