Globally, stakeholders in learning institutions have strived to improve the schools’ physical environments in attempt to enhance learning outcomes of learners. The gist of this study was to establish whether the current status of the physical environment in the public secondary schools in Nairobi County have been mainstreamed to positively influence on the learning outcomes. The objectives of the study were: establish the extent of sufficiency of school land sizes; determine the status of schools land security of tenure; establish the status of maintenance of school buildings and; ascertain the adequacy of facilities for learning. The study adopted the case study research design. Public secondary schools were stratified into boys, girls and mixed categories. A further stratification along eight geopolitical divisions resulted into a sample of 39 schools. Results from a revised Commonwealth Association of Physical Environment (CAPE) questionnaire administered revealed that the overall average quality of mixed schools’ index of 126 was lower than that of boys’ and girls’ schools. The indices for boys’ and girls’ schools were both equal to 134. A framework of improving school facilities from the foregoing results was, therefore, suggested with key features of upgrading old facilities, improve school grounds and controlling physical development around educational facilities