Human Resource Management (HRM) faces difficulties in small businesses which derive from the small size and absence of adequate financial resources. Many authors have investigated the changed version of HRM in small enterprises which is some deal different with HRM in large enterprises. But in Iran researches are not interested in investigating human resource management in the field of small businesses and this encouraged me to perform this research. At first, this study has reviewed HRM policies and practices in small and medium enterprises (SMEs) in the world. Then Iranian medical imaging centers have been selected as knowledge SMEs and some related managerial information has been collected from them by observation and interview. The obtained findings are about the role that HRM plays in today Iranian SMEs in the case of medical imaging centers. In this chapter the type of Human Resource Management which is accomplished in medical imaging enterprises in Iran is discovered and you can find the mistakes performed by their managers. These findings are analyzed based on literatures. In the conclusion part, some differences between western and Iranian models are proved and the study concludes that most of the owner managers in medical imaging centers in Iran could not execute HRM practices, even if they knew them or not. At last, some key points are presented as final recommendations to Iranian medical imaging SMEs in order to help them to improve their efficiency in the future.