Many clinical guidelines were elaborated to improve quality of medical care and to achieve standardization of patient’s treatment. Originally clinical guidelines are written in everyday language and then they are converted into formal model that can be implemented and processed by computer. If all relevant patient’s treatment data are stored in patient’s Electronic Health Record, the guidelines formal model may be, in principle, compared with patient’s data to determine, if the patient was treated according to the recommended clinical practice. In this article we present an algorithm that enables to compare patient’s data record with EGLIF (Enhanced GLIF) model. EGLIF is a simple enhancement of the standard GLIF model and it was devised to render the comparison more transparent and more convenient. Comparing algorithm is proposed for GLIF models with unambiguous decision steps and for patient’s data records containing all relevant patient’s treatment information. Its modification for arbitrary decision steps can be easily done. However, comparing GLIF or EGLIF model with incomplete patient’s data record is more difficult issue. Some suggestions how to tackle this problem are discussed in the conclusion.