IMPORTANCE The optimal treatment for head and neck lymphatic malformations (LMs) is unknown. To our knowledge, this is the first head-to-head comparison of primary surgery and sclerotherapy for this condition. OBJECTIVE To compare surgery and sclerotherapy as initial treatment for head and neck LMs. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study including patients in 2 pediatric vascular anomaly programs receiving treatment for head and neck LMs. INTERVENTIONS Primary surgery or primary sclerotherapy and any subsequent therapy within 1 year. MAIN OUTCOMES AND MEASURES Treatment effectivenesswas measured by (1) need for further therapy after first treatment and within 1 year and (2) change in Cologne Disease Score (CDS). Resource utilization was reflected by total intervention number, hospital and intensive care unit (ICU) days, and tracheostomy placement. RESULTS A total of 174 patients were studied. Their mean (SD) age at presentation was 4.2 (4.7) years; 45.1%were female. The initial treatment was surgery in 55.8%, sclerotherapy in 35.1%, and other interventions in 9.1%. The LMstage ranged from 1 to 5, with similar distributions (P = .15) across initial treatment types; 31.2%of LMs were macrocystic, 34.8% were microcystic, and 33.9%were mixed, with similar distributions across treatment types. Patients receiving sclerotherapy had worse pretreatment CDS subscores for respiration, nutrition, and speech (all P ≤ .02). In univariate analysis, initial surgery and initial sclerotherapy had similar effectiveness after the first intervention (P = .21) and at 1 year (P = .30). In multivariate analysis controlling for lesion stage and type, initial surgery and sclerotherapy did not differ in effectiveness after the first intervention (P = .28) or at 1 year (P = .97). Total CDS and subscale changes were similar between treatment types except for the nutrition subscale. Treatment type did not predict total number of interventions (P = .64), total hospital days (P = .34), total ICU days (P = .59), or higher likelihood of subsequent tracheostomy (P = .36). Higher LM stage predicted more hospital and ICU days and higher likelihood of tracheostomy (all P ≤ .02). CONCLUSIONS AND RELEVANCE In this multisite comparison, initial surgery and sclerotherapy for head and neck LMs were similar in effectiveness and resource utilization. Higher stage predicted greater resource utilization.