Thirty cases of orbital lymphangioma were reviewed. Clinical, imaging, and microscopic findings were integrated to develop a pathophysiologic construct and management guidelines. The basic lesion might be considered an abortive vascular system which arborizes among normal structures. Intrinsic hemorrhage expands portions of the small-caliber network into large blood cysts, prompting clinical recognition. While major hemorrhage led to early surgery in 12 cases, long pretreatment intervals could be analyzed in 17 others. Twelve patients had second hemorrhages of varied magnitude, from 2 weeks to 15 years after initial recognition; five patients did not in an average of 6.8 years. Some blood cysts contracted spontaneously. Among 23 operated cases, 12 patients had major new bleeds from 4 days to 12 years after initial surgery; 11 patients did not in an average of 4.2 years. Poor final visual acuity was associated with multiple surgeries. The authors advocate conservatism in surgical case selection and in operative dissection.