The explosion of cloud services on the Internet brings new challenges in service discovery and selection. Particularly, the demand for efficient quality-ofservice (QoS) evaluation is becoming urgently strong. To address this issue, this paper proposes neighborhoodbased approach for QoS prediction of cloud services by taking advantages of collaborative intelligence. Different from heuristic collaborative filtering and matrix factorization, we define a formal neighborhood-based prediction framework which allows an efficient global optimization scheme, and then exploit different baseline estimate component to improve predictive performance. To validate the proposed methods, a large-scale QoSspecific dataset which consists of invocation records from 339 service users on 5,825 web services on a worldscale distributed network is used. Experimental results demonstrate that the learned neighborhood-based models can overcome existing difficulties of heuristic collaborative filtering methods and achieve superior performance than state-of-the-art prediction methods.