The adenoids and tonsils are thought to be an essential part of the immune system protecting against pathogens invading the upper respiratory tract. They are immunologically reactive lymphoid organs which manifest specific antibodies along with B and T cells activity in response to variety of antigens. This study aimed to observe the changes in humoral immunity in children with chronic adeno-tonsillitis and/or hypertrophy of adenoids and tonsils before and after adeno-tonsillectomy. Patients and methods: This study included 50 children who were classified according to presence or absence of chronic adeno-tonsillitis and/or hypertrophy of adenoids and tonsils into two main groups; Group A (operative) including 25 children that have chronic adeno-tonsillitis and/or hypertrophy of adenoids and tonsils who underwent adenotonsillectomy, Group B (control) including 25 healthy children, to compare their serum immunoglobulins levels with Group A. All children were subjected to full history, clinical examination, routine investigations and measurements of serum immunoglobulins (IgA, IgG and IgM). Two samples of blood were taken, one before adenotonsillectomy and one after three months from Group A, while a single blood sample was taken from Group B Results: There was a statistically significant difference pre-operatively between Group A and Group B with regard to serum levels of IgA, IgG and IgM (P<0.05) with higher level in Group A compared with Group B. There was marked decrease in serum levels of immunoglobulins in Group A post-operative than in pre-operative, while a statistically non-significant difference between Group A post-operative and Group B with regard to serum levels of IgA, IgG and IgM was seen. Conclusion: After adenotonsillectomy, the humoral immunity parameters were found reduced but overall impact on the status of humoral immunity was not significantly changed.