The lack of research about the human work at the Organic agriculture stimulated this Study, which purpose was to characterize and understand the manager's job in managing organic farming. The field research was carried out In two stages. and allowed to investigate managers' work at organic agricultural production units (UPAO) from the interior of Sao Paulo state, through an adaptation of the ergonomics' analysis method (A ET) and structured interviews. The data collected were further interpreted in the light of the complexity theory (TC). It was possible 10 infer that the organic agricultural manager is accountable for a macro production system (vegetable, animal, processing and services). where the manager acts simultaneously as the administrator and also as the job performer The wide products variety offered by the organic agriculture demands an expertise from the manager in Order to deal with the different vegetable specimens and their integration with the remaining production systems. It wax concluded that the work performed by the managers is characterized by the diversity of activities, that need to be prepared and integrated within a macro system, associated with the certification process determinants, in absence of suitable technology context and uncertain and multiple scenarios. It comes to the manager to incorporate and to transform into work practices the ecological, economical and social sustainability principles, which can be contradictory among each other. They can integrate these multiple dimensions through the development and connection of several competences and knowledge, as well as elaborate strategies to overcome multiple difficulties related to the organic agriculture's technological, financial and human aspects.402318324