Purpose Idiopathic inflammatory tumor of the lacrimal gland, also called idiopathic dacryoadenitis, generally is treated with high-dose, long-term systemic corticosteroids, despite their limited success, high recurrence rate, and incidence of drug-induced side effects. This study describes the outcome of patients with idiopathic dacryoadenitis who were managed with surgical debulking. Design Retrospective case series from 2 tertiary referral centers. Participants Forty-six patients (46 lacrimal glands). Methods Review of the clinical records, radiologic scans, and histopathologic specimens, with additional immunoglobulin G4 immunostaining. Main Outcome Measures Clinical signs and symptoms at 2 months after the surgery and off medications. Results Before referral, 41% (19 of 46) of the patients had received systemic high-dose corticosteroids, after which they all showed recurrence, of whom 26% (5 of 19) became dependent on corticosteroids. At referral, all patients underwent debulking surgery of the inflammatory lacrimal gland mass for diagnostic and therapeutic reasons. Additionally, intralesional or systemic low-dose corticosteroids were given during the operation or the first postoperative days in 54% (25 of 46) of the patients. At 2 months after the debulking surgery, a full clinical recovery was seen in 80% (37 of 46) of the patients. A recurrence occurred in 8% (3 of 37) of the patients 4 months and 2.2 and 4.6 years later. Surgical failure (20%; 9 of 46) was correlated with prior corticosteroid treatment (P = 0.002, Fisher exact test), but not with sclerosing inflammation present in 28% (13 of 46). The median follow-up time was 7.2 years (range, 0.7-18 years). Conclusions Debulking biopsy procedures for idiopathic dacryoadenitis, in addition to being diagnostic, may be therapeutic.