Thai language is a proud cultural heritage of Thais. Moreover, Thai language for communication is one of the student core competencies which must be improved through 12 years of basic education in Thailand in order to cope with a rapidly changing trend and live happily in the 21st century. This research was carried out to explore Thai teachers’ problems with teaching Thai language for communication competency for elementary school students. The participants were 120 grade 1-3 teachers from private schools in Kalasin Province, Thailand. The questionnaires were employed to collect the personal information of the respondents and survey their problems. Percentage, mean, frequency distribution and standard deviation were applied to analyze the data. The findings revealed that problems with students’ grammatical and social-communicative competencies (M = 4.32, S.D. = .631) as well as teachers’ teaching management (M = 4.23, S.D. = .618) were at a high level. These provided useful basic information for developing a language for a communication competency-based program in the further phases.