This paper suggests that the urbanization process provides economies of scale which lead to an agricultural transformation through intensification. An example of such a transformation is provided by the rise of urban and peri-urban horticultural activities as a competitive substitute to staple crops, and through an intensification process destined to meet city food demand. To this end, we analysed in Cameroon the horticultural activities among small scale farmers facing increasing population densities (175 inhabitants km-2 in our study area, against 34 inhab km-2 for Cameroon). A town of about 7,500 inhabitants located in the South-West Province of Cameroon was selected and two series of surveys were conducted in 1995 and 2004 among 300 households as well as the local food market. Results revealed that net incomes increased by 14% and farm employment by 20%. Still, farm and food trade incomes declined. In 1995, staple crops accounted for 95% of food crop income per farmer (staple and horticultural crops combined) and horticulture only for 5%. By 2004, horticulture and staple crops represented respectively 42 and 58% of food crop income. At the same time, the share of non-farm income in total income increased from 40% in 1995 to 79% in 2004 which more than compensated the fall of farm incomes. The same trends occurred for household self-consumption as food crop self-consumption declined by almost 80% whereas the share of horticulture in self-consumption increased from 6 to 47%. Horticulture has become the sole growing farming sector in our study area. Its challenge is to maintain a competitive and sustainable intensification process.