Foreign language anxiety (FLA), the pervasive feeling of mild to severe apprehension when faced with communicating in a foreign language, is universally quite common. The manifestation of FLA in Thailand, where English is taught as a foreign language in secondary schools, is no exception. By employing descriptive phenomenology, this study sought to corroborate the existence of FLA at some stage during Thai secondary EFL classes and discover if FLA continues to trouble Thai adults working in international organizations. The population of this study is 12 Thai adults who are working as office workers, management, and administrative staff in an international organization in Thailand. The participants shared accounts of experiencing negative or harsh feedback from Thai teachers and Thai classmates, doubting their English language proficiency, persistent fear of embarrassment when making mistakes in English, and a prolonged feeling of guilt from limited grammatical and vocabulary knowledge while in secondary EFL classes. In the end, all participants disclosed that FLA, which they corroborated began when they were students in secondary school, has continued to plague them in adulthood. The study recommends that to diminish FLA in Thai secondary EFL classrooms, education stakeholders must implement sound language policy changes, progressive educational development, and most importantly, sufficient teacher education and teacher support focused on producing qualified Thai teachers of English.