Horizontal wells generally have a better performance than vertical wells in terms of productivity, but are however more expensive to drill, complete and produce from. This work compares the performance of the two types of wells by estimating Productivity Index (PI) for horizontal and vertical wells under same reservoir parameters and determines which of the two types of wells is more economical. Joshi and Borisov's models for predicting horizontal Productivity Index are adopted in this research, while vertical Productivity Index is predicted using Joshi's model only. Economic evaluations of the two wells are done using investment decision criteria known as the Net Present Value (NPV). Hypothetical data used in all calculations generated results that indicated that horizontal wells have higher productivity than the vertical wells, and that the horizontal wells in this project are more economically acceptable than the vertical wells. In conclusion, Horizontal well Productivity Index increases with increasing horizontal well length while vertical productivity index is not affected by well length. Both horizontal and vertical productivity indices increase with increasing reservoir thickness. It is recommended that subsequent work in this field of study should consider productivity models that account for pseudo-steady state flow and reservoir anisotropy.