Organometallic compounds are widely used in almost all sectors of industry. As a result of emissions from natural and anthropogenic sources they are released to the environment, where they undergo a variety of conversions and interactions. Some organometallic compounds exhibit high toxicity. Organometallic compounds of mercury, tin, lead, selenium and arsenic are among the most common and hazardous compounds. Based on literature dealing with the occurrence and methods of determination of selected organometallic compounds of mercury, tin, lead, selenium and arsenic, we describe their sources, uses and the mechanism of toxicity. Fundamental problems associated with speciation analysis are discussed and the basic steps of analytical procedure used for the determination of organometallic compounds of Hg, Sn, Pb, Se, and As in soil and bottom sediments, including sample collection, preservation, storage, extraction, separation and determination, are characterized.