The objective of this paper was to evaluate the applicability in research and clinical practice of clinical scores for acute asthma in pre-school children. All instruments were reviewed according to a standardized set of criteria: purpose of the score, suitability for use in children, inter-observer agreement, validity and responsiveness. A Medline literature research resulted in 16 different clinical asthma scores, which have been developed to assess the severity of acute asthma, to predict the outcome of an attack, or to evaluate the response to treatment. Most asthma scores could be easily obtained in children. Three scores have been modified to facilitate application in a younger age-category. Inter-observer agreement has received little attention, although all scores contained items that require subjective judgement. The predictive validity was insufficient to justify the application of clinical scores as a decision rule for the admission or discharge of children with acute asthma. Asthma scores seem to be useful for assessing the severity of an attack and evaluating the response to therapy, but as yet there is insufficient information on the performance of the scores to justify a preference. Wheezing and retractions appear to be important items of any useful score for acute asthma.