Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels. This study investigated some haemostatic parameters among diabetes mellitus patients attending diabetes clinic at the Federal Medical Centre Yenagoa; A tertiary health institution. One hundred and eleven individuals participated in this study, comprising 31 females and 25 males (diabetes mellitus patients) and 30 females and 25 males (control subjects). Blood was collected from the participants and the prothrombin time, activated partial thromboplastin time and platelets count were analyzed using standard procedures. Results showed mean values in females and males as 10.84±2.18 and11. 28±0.86 seconds respectively (prothrombin time), 29.26±2.16 and 30.93±2.43 seconds (activated partial thromboplastin time), 401.94±59.20 and 402.20±41.72 x109/L respectively (platelets counts) for the diabetes mellitus patients and 12.74±1.42 and 12.34±1.09 seconds respectively (prothrombin time), 32.81±1.76 and 32.77±1.46 seconds (activated partial thromboplastin time), 263.33±55.32 and 282±51.03 x109/L respectively (platelets counts) for the control groups. There was significant variation (P< 0.002) among both group of subjects for each of the sex. Prothrombin time and activated partial thromboplastin time were significantly lower while platelets counts were significantly higher in the diabetes mellitus patients compared to the control. Lower prothrombin time and activated partial thromboplastin time suggest hyper-coagulability which may lead to adverse cardiovascular and thrombotic complications among the diabetes mellitus patients. While an elevated platelets counts is an indication of increased platelets function which could lead to vascular complications.