In Ogun State, Nigeria, forestry is regarded as a long term, low investment venture (Olawoye, 1975). The introductions of fast growing species such as teak (Tectona grandis L. and Gmelina (Gmelina arborea Roxb) have changed this, hence private forestry seems now to be profitable, if only with these introduced exotic, fast growing species. The present investigation plans to examine the cost profile of input and output in the farming of teak in Ogun State is with the sole purpose of justifying or promoting private tree farming a motive essential to supplement the Government's efforts at regenerating the species in Nigeria. The results of the present study should serve as an empirical basis for the clarification of the belief in Ogun State that most trees spend a long time (gestation period) to reach maturity and equally long time before tree farming can become an economically viable venture. It is hoped that the empirical evidence/clarification enumerated in this study will encourage private investors to come into the plantation forestry sector in Nigeria.