This article aims to evaluate the practice of sustainability among Malaysian Secondary Schools involved in the Sustainable Schools Program Environmental Award (SLAAS). The research attempts to identify the SLAAS effects on teachers' and students' behaviors after direct involvement with the activities of the program. The cluster sampling technique was used in selecting the school samples and the respondents were then also selected through simple random sampling among upper secondary pupils. A questionnaire survey was administered for 247 teachers and 447 pupils, to evaluate the after effects of the SLAAS. Document analysis was employed to identify the greening activities that were carried out in the schools involved. The results showed that the schools' involvement in SLAAS had some transformative effect on the schools especially on greening activities and also on sustainable behavior within the school compound. Based on the correlation analysis, it showed that there was a significant correlation between the knowledge about SLAAS program and the behavior of the teachers and similarly, it was also found that the significant correlation between the knowledge of the SLAAS and the behavior of the pupils post SLAAS. Hence SLAAS must be continuously deployed in school outdoor activities on greening efforts to educate pupils to sustain environmental quality. It is suggested that teachers should play the role model of sustainability, not only for the pupils but also for the public.