The relationship between trade and productivity has not been established theoretically. Some researchers have indeed found some, if not complete, support for the view that increasing openness has a positive impact on productivity. This study used a Cobb-Douglas production function as in Miller and Upadhyay (2000) to estimate the impact of FDI, exchange rate, capital-labor ratio and trade openness on GDP for 38 African countries from 1980 to 2008. Data were transformed to natural logs and estimated using alternative panel models; which included one- or-two-way fixed or random effects models. The results found trade openness having a positive relationship with GDP; which is comparable to findings of Ahmed et al.; (2008).