OBJECTIVE The aim of this study was to determine seizure outcome, functional outcome, and the withdrawal of antiepileptic drugs (AEDs) after conservative or surgical treatment of patients with new-onset cavernoma-related epilepsy (CRE). METHODS The authors conducted a retrospective comparative observational study of 79 consecutive patients, each with a single sporadic cerebral cavernous malformation (CCM) and new-onset CRE. RESULTS Forty-one patients underwent initial surgery (IS), and 38 patients underwent initial conservative (IC) treatment. Of those in the latter group, 19 underwent delayed surgical (DS) treatment. At the last follow-up, 88%, 32%, and 79% of patients in the respective groups had been seizure free for at least 2 years (International League Against Epilepsy [ILAE] Class 1; IS vs IC, p < 0.0001) and 78%, 8%, and 58%, respectively, had been off AEDs (IS vs IC, p < 0.0001). The cumulative probability of staying seizure free (ILAE Class 1) during a 5-year period was 73% (mean seizure-free follow-up 49.8 ± 2.7 months, 95% CI 44.4-55.1 months) for the IS group, 22% (mean 31.8 ± 3.6 months, 95% CI 24.8-38.8 months) for the IC group, and 68% (mean 48.6 ± 4.3 months, 95% CI 40.1-57.1 months) for the DS group (IS vs IC p < 0.001). Long-term operative morbidity was 3%, and long-term morbidity in the conservatively treated group was also 3%. CONCLUSIONS Patients with CCM and new-onset CRE who underwent IS treatment showed better results in seizure control and the discontinuation of AEDs than the conservatively treated patients. Operative morbidity was comparable to the morbidity from symptomatic CCM hemorrhage in the conservative group. Half of the patients who started with conservative treatment underwent subsequent surgical treatment; however, a longer duration of epilepsy prior to surgery did not worsen postoperative seizure outcome.