The main pollution issue associated with the compost production in tunnels is the production of a liquid leachate characterized by high levels of salts and NH4eN as well as high organic load. However, compost leachate may also be considered as a source of nutrients and water and used as fertilizer. The raw leachate could be used as potential fertilizer because it meets the requirements usually established for commercial fertilizers. An economic estimation showed that the production cost of leachate as fertilizer is low and that an interesting profit margin could be obtained through the commercialization of the compost leachate as fertilizing liquid.