Decommissioning offshore petroleum production activities have been progressively increasing the concern of the industry, government and distinct interest groups through the last years. There are at least two reasons for this sudden regard: first it is the maturing of several oil and gas fields around the world hi recent years; second, it is the growing impact of environmental concerns in international affairs.Although several works published address to some techniques and to potential problems/risks related to decommissioning of offshore oil and gas production installations, its operations (mainly their methodology) are in some extent an innovative issue, especially in Brazilian's fields.Therefore, the first motivation for this article is the novelty of this subject in the country, since Brazilian national industry is just beginning to deal with the end-of-leasing obligations, which will involve decommissioning operations. Besides, the absence of a complete official regulation developed by the Government, through its competent regulatory agency.The present paper comprehends a concise review of decommissioning offshore oil and gas production activities, including surface and sub-surface installations, predominantly based on European scenario due to its similarity with Brazilian's fields in some of its complex aspects. It also emphasizes which may be the methodology to achieve the 'Best Practicable Decommissioning Option' for present offshore production system, which comprise fixed and floating production systems. The current review shows the contemporary international scenario, which may be useful for both: industry and government regulatory agency. For the industry, it could give a significant upgrade to decommissioning operation programs. While for the government it could be useful in outlining specific regulations for decommissioning offshore installation. To sum up, the main ambition of this paper is stimulate debate about the pertinent issues as well illustrate some of the new ideas concerning decommissioning offshore production systems.1 2128Brent Spar Dossier: The Story, Photographic Record, Feature Stories, Press Releases and Technical Data, , www.shell.com/uk-en/directorv/0,4010,25268,00.html, [On-line], [01/2001]Meenan, P., (1998) Technical Aspects of Decommissioning Offshore Structures, , article from Decommissioning Offshore Structures, SPRINGER-VERLAG, London, Great Britain, IBSN 3-540-76213-2Scientific Group on Decommissioning Offshore Structures (1996) First Report, A Report by the Natural Environment Research Council for the U.K. Department of Trade and Industry (DTI)(2000) National Energy Balance, , Brasilia(2000) Annual Statistical Report of Brazilian Petroleum Industry(1999) Annual Report(1981) Law No 6,938, 6938. , August 31 st(1997) Law No 9,478, 9478. , August 6 th(1998) Decision 98/3 on the Disposal of Disused Offshore Installations, , www.ospar.org, Reference number: B-9.6, [On-line],[11/2000](2000) Guidance Notes for Industry: Decommissioning of Offshore Installations and Pipelines under the Petroleum Act 1998(1995) The AURIS ReportHughes, N., Fish, P., (2000) Decommissioning: Addressing the Issues - When? What? How? And How Much?, , Foster Wheeler ConsultingGriffin, W.S., (1998) Managing the Platform Decommissioning Process, , SPE International Conference and Exhibition, Beijing, China, (SPE 48892)Pittard, A., Technology Field Abandonment Costs Vary Widely Worldwide (1997) Oil and Gas Journal, 95 (11)Graff, W., (1981) Introduction to Offshore Structures, , Gulf Publishing Company, Houston, Texas, IBSN 0-87201-694-3www.petrobras.com.br, [On-line]Prasthofer, P.H., (1997) Offshore Production Facilities: Decommissioning of Topsides Production Equipment, , Proceedings: Public Workshop, Decommissioning and Removal of Oil and Gas Facilities Offshore California: Recent Experiences and Future Deepwater Challenges, Ventura, California, (MMS OCS Study 98-0023)(1999) Drilled Wells Abandonment Regulation, 176. , Regulation