ObjectiveTo evaluate the longterm clinical outcome of Gamma knife surgery(GKS) for vestibular schwannomas(VS) with neurofibromatosis Ⅱ (NF2) and the role of GKS in the comprehensive treatment of this tumor.Methods60 patients with NF2 underwent GKS from Dec.1994 to Dec. 2008 and followed up for more than one year after GKS were included in our study. Of them, 27 were male and 33 were female. Their age ranged from 12 to 59 years old with a median age of 30. Of 120 VSs in the 60 patients, pure craniotomy, dynamic observation and GKS was applied in 14, 13 and 93 respectively. Of the 93 VSs, pure GKS and GKS after craniotomy was adopted in 74 and 19 respectively.ResultsThe followup period ranged from 12 to 245 months with a median of 100 months. The tumor control rate of VS with NF2 was 77%. The cumulative tumor control rates of 3,5,10 and 15 years were 96%, 94%, 80% and 70% respectively. The longterm hearing preservation rate was 25%.The cumulative hearing preservation rates of 3,5,10 and 15 years were 89%, 81%, 47% and 19% respectively.ConclusionGKS has been confirmed to have longterm local tumor control for VSs of small to medium size. However, the tumor control rate and hearing preservation rate of VS with NF2 were lower than those of unilateral sporadic VS. The therapeutic effect of Wishart type VS is poor due to its rapid progress. Phenotype is the most important factor in predicting the final outcome of GKS for NF2.