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This document is the final version of the report of the MedSudMed Acoustic Survey carried out in Libyan waters from 06 August to 02 September 2010 on board of the R/V Maria Grazia. The document presents also the results of the processing of the data collected during the survey. The survey was carried out under the cooperative framework promoted by the FAO MedSudMed Project (Assessment and Monitoring of the Fishery Resources and the Ecosystems in the Straits of Sicily). The main objective of the survey was to gather information on the biomass and spatial distribution of small pelagic fish and on some environmental factors along the Libyan continental shelf. To this extent, acoustic measurements of small pelagic fish were carried out. Sampling of small pelagic fish using a pelagic trawler was carried out as well. During the survey, advantage was also taken to measure some physico-chemical parameters of the water column. The acoustic survey was the second survey for the assessment of small pelagic fish biomass after the MedSudMed-08 Acoustic survey carried out in 2008 in Libyan waters. Previous surveys were carried out in 1993-1994. An overall description of the sampling scheme, of the area explored and of the methods adopted is provided. The biomass, abundance, spatial distribution, length frequency distribution and length weight-relationship for the main small pelagic species found in Libyan waters is described: Engraulis encrasicolus, Sardina philcardus, Sardinella aurita, Trachurus mediterraneus, Scomber japonicas, Boops boops, Spicara spp. and Etrumeus teres. Sea water temperature, salinity and oxygen along the water column are also illustrated.