Different governments and international organizations have shown interest in agroecology as a promising pathway for transition to sustainable agriculture. However, the kinds of innovation needed for agro-ecological transition are subject to intense debate. The scale of this debate is itself an indicator of the complicated relation between innovation and sustainability in the agro-food arena and beyond. This review paper analyses the potential of agro-ecology in agricultural sustainability transitions. It also explores whether agro-ecological transition is a sustainable innovation (cf. ecological, green, open, social, responsible). Furthermore, the paper investigates the potential contribution of agro-ecological transition to sustainability, using the 3-D (Direction, Distribution and Diversity) model of the STEPS centre. Agroecology is one of the few approaches that can harmoniously combine innovation and sustainability in agriculture while promoting genuine transition to agro-food sustainability since it embraces all dimensions of sustainability (environmental, economic, social/cultural/ethical). Nevertheless, it can be taken for granted neither that all traditional practices can be classified as ‘agro-ecological’ nor that all farmer-led innovations can be included in the agro-ecological repertoire. Moreover, the relationship between the three aspirations of agroecology (science, movement and practice) needs further elaboration in order to maximise potential for agriculture transition.