Primary non-Hodgkin lymphoma (NHL) of lacrimal drainage system (LDS) is quite rare in children, but it is important to expedite early diagnosis in an effort to alter possible life-threatening disease since they are usually misdiagnosed as chronic dacryocystitis. In the literature, there are few examples of tumors of LDS in children. The authors herein report two pediatric cases of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) originating from lacrimal sac in an attempt to increase the knowledge about the clinical course of NHL of LDS. Considerable care must be taken since tumors of lacrimal drainage can mimic dacryocystitis clinically and macroscopically. Two patients both attended with painless swelling in the left lacrimal sac region and epiphora of the left eye. Orbital magnetic resonance imaging showed a tumoral lesion in the left lacrimal sac region and histopathological examination of excisional biopsy specimen demonstrated MALT lymphoma in both patients. The treatment regimen comprises lacrimal sac excision within the tumor, canalicular dacryocystorhinostomy (DCR) with bicanalicular silicone intubation (BSI) combined with chemotherapy and regional radiotherapy in one case, whereas the second case received only radiotherapy after canalicular DCR with BSI. Both of them maintained clinical remission along follow-up.