Previous reports have suggested that the incidence of tonsillectomy, and/or tonsillitis in children, is influenced by factors such as parental smoking, maternal health and previous parental tonsillectomy. The reports have considered single factors and have not considered the possible confounding effect of the factors upon one another. Previous studies have not investigated the influence of social class. This paper uses the background of a large case-control trial of children awaiting tonsillectomy for recurrent tonsillitis, and a normal control group to study the influence of parental smoking, parental surgical history, parental tonsillectomy, family atopy and social class upon the reported incidence of sore throats and tonsillitis. A multivariate analysis is used. The paper shows that parental smoking, previous parental surgery and social class have no effect upon the number of sore throat episodes. A history of parental tonsillectomy and a family history of atopy are both significant predictive factors for the number of reported sore throats and episodes of tonsillitis in children.