The lipidic fraction compositions of both concentrated vinasses, a by-product of the sugar industry, and a compost made basically from olive oil vegetation waters (alpechin) were studied. The alpechin lipids are composed mainly by series of n-alkanes and lineal and branched fatty acids, whereas the major lipids in vinasses were n-alkanes, n-alkanols and acetals. Concentrations and composition of lipids in both materials do not seem of concern. Preliminary results on the effects of the application of both materials over two years on the organic status of an agricultural soil are also reported. No significant changes were observed in total organic carbon and contents in humic fractions and lipids before and after the applications. However, analysis by GC-MS of the lipid compounds present in bound forms in the subsoil layer revealed that some hydrophobic components were accumulated in the soil following the waste applications. © 1992, Taylor & Francis Group, LLC. All rights reserved.