The country placed 18th in the Doing Business 2013 survey released on Tuesday, down from 17th in the 2012 rankings, and 16th in the 2011 report.
The country ranked 85th for starting a business, a slide from 78th in 2012, but its ranking for ease of paying taxes improved to 96th from 100th a year ago.
The World Bank praised the kingdom for reducing the corporate profit tax and showed positive outlook for Thailand in attracting investors.
"Government agencies in Thailand have been collaborating to promote a friendly business environment,'' said Annette Dixon, the World Bank Country Director for Thailand, said in a press release. "This, along with other measures such as improving the quality of education and promoting innovation, will help Thailand attract investors and remain competitive.''
The bank also hailed Thailand's efforts to reduce the procedures needed in registering a company in Thailand.
"Thailand continues its efforts to reduce the cost and time of doing business. This, combined with reforms aimed at improving skills and promoting greater competition in the services sector, would promote greater investment and improve business operations,'' said Kirida Bhaopichitr, the World Bank senior economist for Thailand.
Among other key indicators, the country ranked 16th for dealing with construction permits, 10th for getting electricity, 70th for getting credit, 13th for protecting investors, 20th for trading across borders, 23rd for enforcing contracts and 58th for resolving insolvency.
The countries surveyed are ranked on their ease of doing business, from 1 to 185. A high ranking on the ease of doing business index means the regulatory environment is more conducive to the starting and operation of a local firm.
The report covers the June 2011-2012 period and uses data for indicators that measure regulation affecting 10 key areas.
Singapore was still on top of the ranking for seven consecutive years, followed by Hong Kong. Other countries in the top 10 were New Zealand, the United States, Denmark, Norway, the United Kingdom, South Korea, Georgia and Australia.
In Southeast Asia, only Malaysia stayed above Thailand at 12th in the report. Brunei was in 79th, Vietnam stayed at 99th, the Philippines ranked 138th and Laos was 163rd. Indonesia, Myanmar and Cambodia were not in the survey.