This study investigates how teachers' perceptions of school environment factors, teaching efficacy, teacher stress and job satisfaction, and to determine whether gender was a differentiating factor. A total of 387 Vietnamese junior high school teachers completed one questionnaire for four sections about school-level environment, teaching efficacy, teacher stress, and job satisfaction. The results reveal that most of these teachers had high perceptions of school-level environment factors (principal leadership, mission consensus, professional interest, affiliation, student support, innovation, resource adequacy), teaching efficacy (classroom management, student engagement, and instructional strategies), job satisfaction, and teacher stress (classroom stress and workload stress). Results also show that statistically significant differences were found between females and males on the mean scores of school-level environment factors, teaching efficacy, stress, and job satisfaction. Female teachers scored higher than male teachers on both stress while male teachers scored higher than female teachers on school-level environment factors, teaching efficacy and job satisfaction. Male teachers with less stress had higher perceptions of school-level environment factors, higher teaching efficacy and higher job satisfaction, whereas female teachers with greater stress had lower perceptions of school-level environment factors, lower teaching efficacy and lower job satisfaction. Educational implications of the findings are discussed.