We retrospectively reviewed the complication rate associated with silastic tube intubation in the treatment of congenital and acquired obstructions of the lacrimal system in 82 patients with a follow-up of 3 to 66 months. Complications included tube prolapse, extrusion or breakage, punctal erosion, conjunctival irritation, intranasal discomfort, and tube inspissation with mucoid debris ("dirty tubes"). The rate was highest in the first 3 months (41%); it decreased to less than 10% after 6 months. Based on these findings, we recommend that silastic nasolacrimal tubes be regarded as semi-permanent devices which may safely be left in place for years.