The objectives of this study were to identify the factors that influence adoption and integration of ICT in teaching; determine significant relationship between the personal level and technological level factors and the adoption and integration of ICT in teaching, and test the significant difference in the influence of the factors on the adoption and integration of ICT in teaching. Respondents of this study are 123 foreign teachers from different primary and secondary Schools and international schools in Thailand through the use of snowball sampling technique. They are non-education graduates, were teaching in various schools in Thailand, were enrolled in the Academic Year 2017, and those that are currently taking the Graduate Diploma in Teaching Profession in one of the private international universities in Rangsit and Nakhon Nayok, Thailand. This study utilized the descriptive method. The instrument utilized for gathering the data was a researcher-made survey questionnaire which was tested for its validity and reliability. The data were statistically analyzed and interpreted through basic statistics, such as frequency, percentage, and mean; and inferential statistics, such as Spearman rho, Pearson product moment correlation coefficient (Pearson r), t-test for significant difference, and Analysis of Variance (ANOVA). Findings revealed that foreign teachers agreed that factors such as personal characteristics and technological characteristics influenced the adoption and integration of ICT in teaching. It was also found out that in general there was no significant relationship and difference in the personal and technological characteristics to the integration and adoption of ICT in the teaching-learning process.