The existence of comovement across different sectors is an important feature of the business cycle definition. The purpose of this work is to characterise the Portuguese sectoral business cycle, with particular emphasis on the comovement phenomenon, for the years 1953-2003 in terms of both GVA and employment. Inthe last fifty years substantial structural changes were observed in the Portuguese economy. These changes mean that some sectors, notably the service sectors, are growing in relative terms. Despite the existing differences in characteristics, such as trend and volatility, there is evidence for the presence of comovement among Portuguese activity sectors. A discussion on the causes of such phenomenon, such as the input-output linkages, in light of the Portuguese economy is done.