1964 Obayashi Corp. began business activities in Thailand under the leadership of Shoji Shigeno. Commencement of construction of AlA Bldg. The first use of a protection sheet to prevent accidents in Thailand was widely acclaimed.
1966 Award of construction work of SEATO Headquarters and Japanese Embassy in Thailand.
1967 Dusit Thani Hotel project, a renowned landmark on Silom Road, started.
1968 Kenjiro Yoshino assumed directorship of Bangkok Representative Office.
1970 Completion of Sumitomo Thaniya Building as Thai Obayashi Corp., Ltd. "s Head Office.
1971 The largest projects completed were Toyota Motor Thailand, National Thai and Yakult (Thailand) factories.
1972 Major Projects completed were ESSO Building, West German Embassy, Royal Bangkok Sports Club and huge Chulabhorn Dam for EGAT.
1974 Establishment of Thai Obayashi with Sommai Hoontrakool inaugurated as first chairman and Tadanao Murakami as President.
1977 Began sending Thai Obayashi staff annually for training at Obayashi Corporation in Japan. Sukeyoshi Morishita appointed as Thai Obayashi President. Main woks of this year were MWWA Water tunnel & pump facility, factories for Thai Suzuki Motor and Thai Otsuka Pharmaceutical.
1980 This year"s main project was the Bangkok Bank Head Office, introducing Thai Obayashi"s unique "OWS System" to Thailand.
1981 Thai Obayashi finished construction of Official Residence of the Japanese Ambassador of Thailand and Obayashi Corporation completed Youth Welfare Center and Rice Storage Laboratory Center.
1982 Suthas Theeradhnakorn inaugurated as new Thai Obayashi Chairman and lehiro Matsui as President.
1984 10th Anniversary of Thai Obayashi Corp., Ltd. Construction of Minebea Thai Ayutthaya factory, etc.
1986 Construction of Minebea Thai, Bangpa-in bearing & printer plants, etc.
1989 Sommai Hoontrakool reassumed Chairmanship of Thai Obayashi and Shigeo Takanashi was appointed as President.
1991 Construction completed of Nantawan Bldg, Ratchadamri as Thai Obayashi"s new Head Office.
1995 The Bangkok"s latest remarkable construction, the Siam Commercial Bank Head Office (SCB Park Plaza) at Ratchayothin was completed this year.
1997 Major projects completed were Tripetch lsuzu Sales Service Center, Siam Discovery, Siam Tower, etc. Economic crisis and depreciation of Thai Currency
2000 ISO 9001 certification for Thai Obayashi"s Quality Management System. Completion of 4 major branches of hyper market, the Tesco Lotus in Bangkok, etc.
2001 Major projects completed were the 5 stars JW Marriott Phuket Resort and Spa, Shinawatra University (a new international University of Thailand in Pathumtani), etc.
2003 Sompong Chintawongvanich appointed as the first Thai President. Completion of Thailand"s first underground subway MRT Chaloem Ratchamongkhon Line. Also, the construction of Suvarnabhumi Airport, Bangkok"s second international airport was under progress as plans.
2004 30th Anniversary of Thai Obayashi Corp., Ltd. and 40th Anniversary of Obayashi Corporation since the first establishment in Thailand.
2005 Major projects completed was Siam Paragon, a remarkable world class shopping mall in the heart of Bangkok.
2006 Major projects were the Borom Rachasathit Maholan Throne Hall, Toyota Banpho Plant, and the Embassy of Japan.
2007 Major projects completed were Asia Center Office Tower and Anantara Resort & Spa in Phuket
2008 Major projects completed were Marriott Timeshare Phuket Phase 3, Anantara Resort. Obtained certification of ISO 14001 for Environmental Management System.
2009 Major projects completed were the Architect Council Office and Asian Stanley Phase 3.
2010 Major projects completed was the Bangkok University Landmark.
2011 Obtained certification of OHSAS 18001 for Occupational Health & Safety Management System. Sompong Chintawongvanich appointed as the first non-Japanese Executive Officer of Obayashi Corporation in Japan.
2012 Major projects completed were the Park Ventures Ecoplex (LEED Platinum Certified Building) and Amata Castle.
2013 Major projects completed were TMT Gateway Plant No. 2 and Canon Hi-Tech Phase 3
2014 Thai Obayashi 40th Anniversary and Obayashi 50th Anniversary in Thailand. Major projects included the AIA Sathorn Tower.
2015 First launch of Thai Obayashi Training Center in Chonburi. It is the first "TOTAL CONSTRUCTION LEARNING CENTER" of Thailand. Thai Obayashi Training Center was recognized and certified by Ministry of Labor, Council of Engineers and Architect Council of Thailand.
2016 Major projects completed were FYI Centre and Sindhorn Residence.
2017 Major projects completed was AMEC Elevation Test Shaft.
2018 Major projects completed were Sindhorn Lumpini and Sindhorn Tonson.
2019 Thai Obayashi 45th Anniversary together with appointment of the Vice Chairman "Mr.Sompong Chintawongvanich" and the new President "Mr.Pornchai Sittiyakorn". Major projects completed were ICONSIAM and Samyan Mitrtown.