This research aimed to study the knowledge and attitudes of Thai journalists towards the OfficialInformation Act, B.E. 2540, how it is used and problems using this Act. Data from 345 journalists (225journalists from 75 provinces and 120 journalists from the Bangkok area), and in-depth interview datafrom 9 journalists who have filed complaints for the disclosure of official information from governmentorganizations, were analyzed using frequency distribution percentages, mean and standard deviation,and Chi-squares. The findings were as follows.1. Most journalist had positive attitudes towards the Official Information Acts, B.E. 2540.2. Knowledge of the journalists regarding the Official Information Act, B.E 2540, had nostatistically different relationship with attitudes towards the Official Information Act , B.E. 2540, and oftheir use behavior, but had a statistically different relationship with the usage of the Act at a significantlevel of 0.05.3. Length of employment had no statistically different relationship with attitudes towards theOfficial Information Act, B.E. 2540, and use behavior of the journalists in general (except the access toinformation on complaints filed with the concerned offices at the significant level 0.05). However, it wasfound that the duration of employment had a statistically different relationship with the usage of the Act atthe significant level of 0.05.4. Attitudes of the journalists towards the Official Information Act, B.E. 2540, had no statisticallydifferent relationship with the use behavior, but had a statistically different relationship with the usage ofthe Official Information Act, B.E.2540, at the significant level of 0.05.5. The journalists pointed out two problems concerning the use of the Official Information Act,B.E.2540; 1) government organizations were reluctant to disclose the requested information, and 2) thejournalists needed more alternate access channels to official information from those specified in the Act.