Objective: To calculate the rate of rejected specimens received in hematology laboratory stratified by area of collection and reason of rejection. Design: Retrospective study conducted at Prince Hamzah Hospital, Amman/Jordan over a six months period; January 1, 2011 to June 30, 2011. Data were retrieved from the laboratory records. Results: The rate of specimen rejection was highest in the medical ward and clotted specimens were the commonest cause for rejection followed by wrong patent identification. Conclusion: A constellation of factors, mainly related to phlebotomy technique and wrong patient identification are the reasons for rejection of specimens in the hematology laboratory, which necessitates investigating the practice of blood sample collection, and that lesser proficiency of the nursing staff in phlebotomy and importance of correct patient identification may be reasons for this observation.