Historically, the main farming areas in Collserola were the Baix Llobregat and Vallès valleys. Today, however, agricultural activity in the Serra is located mainly around the outskirts of the Park. On the Vallès county side, the few farms that still exist here are located on lower land and are relatively large, with a structure that can generally be defined as farmhouse, family market garden and dry farming fields. On the other hand, towards the River Llobregat the total cultivated area is much larger, but land ownership is much more dispersed, production is more diversified and farms and plots are smaller in size.

Management of agriculture in Collserola requires, above all, preventing further losses of farmland and encouraging the cultivation of abandoned fields using environmentally-friendly methods, promoting ecological agriculture and fostering the maintenance and revival of traditional varieties. One of the lines of action in the programme to promote fauna in the Serra focuses on maintaining cropfields and experimental crops on public estates.

Traditionally, agricultural activity in the Serra was accompanied by a certain complementary amount of livestock farming. As cultivated land and the country lifestyle have been abandoned, much of this livestock farming has become marginal, a merely subsistence activity.

In 1995, the controlled reintroduction of flocks of sheep began in order to help maintain reforested areas, fire prevention strips, thatching grass meadows and other zones occupied by open vegetation, always with the aim of reducing vegetation in such zones as part of fire prevention measures. The reintroduction of livestock farming is also aimed at strengthening an economic activity that contributes to sustainable development in the Serra.