Data on levels of persistent organochlorine pesticides (OCPs) that exhibit potentially harmful effects to the environment all over the Portuguese coastal sediments were scarce. Therefore, in 2007-2008 12 OCPs were surveyed in surface sediments from 11 coastal sites (estuarine or lagoonal) covering north, centre and south areas of Portugal. Analyzes were performed using a previously validated method, involving pre-extraction of OCPs from sediments assisted by microwave and headspace solid-phase microextraction followed by gas chromatography with electron capture detection for quantification and mass spectrometry for OCPs identification. Measurable levels (0.08-26ng g(-1)) of alpha-hexachlorocyclohexane (alpha -HCH), gamma-hexachlorocyclohexane (lindane), aldrin, dieldrin, endrin, 4,4'-DDT, 4,4'-DDD, 4,4'-DDE, heptachlor, heptachlor epoxide, endosulfan I and methoxychlor were observed in all cases. In few cases, the found levels denote the probability of occurrence of adverse biological effects.