The aim of this e-book is to reflect the consolidation and maturity of Portuguese and Spanish research into work teams in organizational contexts. This collection of papers is particularly timely. The dominant lines of research presented here are demonstrably linked to the main thrust of scientific research in other European Union countries and in the US, while Portuguese and Spanish researchers collaborate freely with scholars from abroad. In this sense, the Guest Editor suggests, the area of work team effectiveness has developed its own identity both in each country and internationally.