Noonan syndrome is a relatively common disorder which is usually diagnosed in childhood because of the presence of distinctive facial features, short stature and cardiac anomalies. Previous clinical studies of Noonan syndrome have suggested that autoimmune disorders may be another possible manifestation and there have been two recent reports of Noonan syndrome patients with systemic lupus erythematosus. In this report we present an 11-year-old boy with Noonan syndrome and systemic lupus erythematosus, supporting the previous observations of an association between these two conditions.