In this work, a new methodology, known as the cradle to the cradle, is proposed for the life cycle assessment (LCA). The environmental impacts generated in the production of biodiesel from castor oil are evaluated, taking into account that a percentage of the total residues is fixed by the nature thanks to the different biogeochemical cycles. Data and calculation procedures were collected to quantify the environmentally relevant material and energy flows of the system in study; also, the biogeochemical cycles were integrated along with the models pertaining to the different phases of the cultivation, the industrial transformation, the use as biofuel and the residue disposal. The categories of impact studied were: global warming, acidification, eutrophication, photochemical smog formation, respiratory effects and non-renewable energy. This gave as a result the environmental profile of the system in study.