This unique and first-time research explores the parameters of effectiveness among HIV/AIDS and development NGO managers in India. The aim of this research has been investigate and explore how these managers perceive and view their own effectiveness at work. This research contextualises Analoui's Model (1999, 2002) of eight parameters of managerial effectiveness and three contextual factors, which explores and identifies the inter-relationship between the factors and causal influences which form the basis for their increased effectiveness. The methodology employed include qualitative semi-structured individual interviews with 16 NGOs managers and 2 focus-group interviews with 16 non-managerial staff. The results revealed a myriad of factors and influences concerning the NGO managers’ perception, managerial skills and competencies, organizations criteria for effectiveness, opportunities, demands and constraints involved, as well as the inter-organisational relationship and the dominant managerial philosophy of effectiveness. All the parameters of effectiveness and contextual factors of the Model (1999, 2002) apply and are suitable for this context, however, based on the main findings and in-depth discussions, the model has been adapted and modified in order to fit this unique and complex, highly diverse, holistic, multi-faceted and culturally specific context. The findings also indicate to numerous inter-linked factors both internally and externally of the NGOs and, include various training and development (T&D) needs for managers, with implications for the formation of adequate policies and implementation of relevant development programmes to improve and increase NGO managers effectiveness in India.