Predicting behaviors is particularly important in the field of environmental management because the environment is greatly influenced by human behavior. This paper aims to contribute to the development of an extended theory of planned behavior (TPB) and to gain some insight into the motives for employees' intentions to implement green practices in Algeria as a developing country. Data were collected from the convenience sample of 182 employees in three Algerian cities using a questionnaire survey. The results indicated that attitude toward behavior, subjective norms and environmental knowledge is positively and significantly affect employee's intention to implement green practices. The results also suggested that perceived behavior control had no significant effect. It is expected that the results of this paper can aid policymakers and stakeholders in drafting and implementing sustainable environmental regulations in the workplace.