This paper aims to provide a waste classification model to identify most of the problems encountered in the hospitals sector. The problem of identification & classification of waste is one of the major obstacles that encounter the Lean approach in its implementation in hospitals. This paper established a SWOT matrix that is the subject of detailed analysis of the waste classification phase. This analysis allows to criticize the proposed classification that focus only on specified sources of waste which can have a negative impact on the waste elimination operation. We propose an extended classification that takes into account the three forms of waste in Lean approach.