The pattern of changes and adjustments in the structure of an economy is an issue of consideration in determining tax performance. Most countries inclusive of countries within ECOWAS sub region have recorded major structural changes over the years and this no doubt has a bearing on tax performance in particular and the economy in general. Structural changes was considered as changes in sectorial shares as it relates to output, productivity growth while tax performance was considered in terms of the ratio of taxes to GDP and the structure of taxation in a panel of fifteen (15) countries of the ECOWAS sub-region covering the period of 2000 to 2017. To this end, varied theories were reviewed while the data set were processed and descriptively presented as it relates to structural changes and tax performance in ECOWAS. It was observed that structural changes did not remarkably reflect in improved tax performance owing to factors such as weak tax laws, ease of paying taxes, high of tax rates. It was then recommended amongst others that there is need for ECOWAS sub region to ensure structural adjustments that are market-based and effectively guided by policies and institutional enforcements.