In this study, a new sample of 38 manufacturing firms from Cameroon is examined for the period 1980-95. A production function and an export function are estimated in order to study the determinants of Total Factor Productivity (TFP) and export performance. The results demonstrate a mutually reinforcing relation between productivity and manufacturing export performance. Moreover, the study provides evidence indicating that adequate management of the real exchange rate is a crucial factor for the promotion of manufacturing exports. The performance of the manufacturing sector in Cameroon has deteriorated substantially since the mid 1980s. This decline is to a large degree explained by Dutch disease symptoms and inward looking policies for the manufacturing sector, resulting in a highly overvalued Real Effective Exchange Rate (REER). Based on the estimated export and production functions, a model is constructed to assess the cost of this REER evaluation, both in terms of productivity and exports.