Sustainability of agricultural practices is a suitable concept to evaluate both agronomic and economic performances of conventional agriculture and conservation agriculture. In this study, the concept of sustainability is analysed through its three main components: economic sustainability also called economic efficiency, dealing with the ability of the farming system to ensure sufficient and competitive output production to fulfil market and population needs; social sustainability or social equity, dealing with agricultural ability to ensure equitable revenue or return to different stakeholders of the agricultural production chain; ecological sustainability, dealing with intergenerational preservation of the environment referring here to the sum of natural resources used to ensure agricultural production such as soil fertility. Ecological sustainability is commonly the only aspect of sustainability taken into account by agronomists. Sustainability of conventional agriculture is addressed in this study in small-scale cottonbased agriculture surveys in northern Cameroon. Economic efficiency of cotton in conventional agriculture is analysed through a multi-year data base of a permanent agricultural survey of SODECOTON (Cotton Development Company), while social equity is addressed based on different production cost distribution within cotton production stakeholders. Ecological sustainability is analysed through agronomic variables such as yield variation over time, and mainly soil fertility evolution. Results of the study revealed that economic efficiency of cotton cultivation in conventional agriculture, after attaining acceptable levels in the early 1990's mainly due to high yields and prices and low inputs cost, is now declining. Fertiliser prices for example varied from 500 US $ per ton in 2005 to more than 1000 US $ per ton in 2008. Social equity even if strongly reinforced by an equalizing prices approach and inputs cost determination system, is limited with a hig