With the growth over the past 25 years in the establishment of residential environmental education (EE) centers, what factors EE center directors identify as important to the success of these centers merits discussion. Research in environmental education is still relatively new, with few continuously contributing researchers and a lack of agreement as to what should be evaluated to determine whether or not an environmental education center was successful. There has been little research directed towards the success or effectiveness of particular environmental education centers and what contributes to that success in the minds of EE center directors. As such, the purpose of this study was to determine what factors EE Center Directors deem as significant to the success of their particular EE Center. Study showed that a group of 23 EE Center Directors indicated that a good staff, strong curriculum, and quality facilities were the determinants of success most frequently mentioned. (Contains 2 tables.)