The municipal term mainly occupies a mountainous area located at the northern end of the Sierra del Ordal, which descends to the north to form the lower valley of the Noya river before flowing into the Llobregat river. The vegetation in the mountainous area is typical of the Catalan pre-coastal mountains, mainly pine forest with

Mediterranean shrub understory. The valley area has been used for cultivation, mainly grapes with which wines and cavas of the Penedès Denomination of Origin are made.

Its location on a hillside is the cause of its great variation in height above sea level: the lowest inhabited point in the municipality is 86 meters, at the railway station. The midpoint of the main nucleus (Gelida) is 199 meters from the Church square, and the maximum within the town is the castle (290 masl) and the Martivell urbanization (275 masl). The maximum height of the municipality is recorded in the Puig de les Agulles, 652 meters.

The aforementioned Noya River crosses the term from southwest to northeast, providing a constant water supply for both urban and agricultural consumption. Within the same term there are numerous torrents that flow into it, as well as a large number of sources of drinking water. The climate is typically Mediterranean, with average annual temperatures of 16 degrees Celsius and an average annual rainfall of 550 liters/square meter.