Using the Smiley analogue scale we investigated the correlation between the self-assessment of defined pain by children and the estimation of this pain by parents, nurses and physicians. In addition, the correlation was studied between the patient's mood and the pain intensity stated by himself and by others. The results of 111 patients, aged from 2(9)/12 to 17(6)/12 years, exhibited a high correlation between the self-assessments of pain intensity and pain duration by all three observing groups. Between patients and parents the best correlation was observed in the estimation of severe pain. All three observing groups inclined mainly to over- than to underestimate the pain intensity. This behavior pattern was mainly observed in parents. The patient's emotion did not influence the self-assessment of pain intensity and pain duration. But a great correlation was observed between the patient's emotion and the pain assessment by all three observing groups. Using a Smiley analogue scale the pain assessment by children or by others is a helpful tool for an individual pain therapy in the daily clinical routine.