Objective: The clinical spectrum of childhood non-Hodgkin's lymphoma (NHL) is different from that in adults, with frequent extranodal involvement. We searched the incidence and radiological appearance of the secondary involvement of the thyroid and salivary glands by ultrasonography (US) to assess its importance for staging of the disease. Materials and methods: We examined the thyroid, parotid and submandibulary glands of 43 children with NHL, age ranging between 9 months and 17 years, by US. Results: According to US findings, involvement of the parotid gland was very common as detected in 18 of the cases with NHL (41%). It was the most common organ involved in lymphoma. Lymphomatous infiltration of the thyroid gland, with bilateral multiple focal lesions, was detected in two patients and proved by fine needle aspiration biopsy in all cases (5%). Salivary gland and thyroid involvement changed staging in three (6%) of the patients, however, the treatment plan was unchanged. Conclusions: This study shows that anatomic sites, known to be very rarely involved at the initial presentation of the disease is actually more commonly involved in childhood NHL. However, it does not cause any significant change in the treatment planning or in the survival. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.