We evaluated the effectiveness of MEWS and biochemical parameters in predicting outcomes for acute medical admissions. Data from consecutive admissions to the Acute Medical Unit (AMU) of National Hospital of Sri Lanka were collected. C-reactive protein (CRP), albumin, white cell count, platelet count and haemoglobin values were collected. Adverse endpoints were HDU/ICU admission,cardio-respiratory emergency/resuscitation and death. A MEWS score of >=5 together with increasing age,pulse rate, respiratory rate, AVPU score, CRP,CRP/Albumin ratio and reduced platelet and albumin levelall increased the odds of reaching "adverse endpoints". Adding a score for biochemical parameters increased the area under the ROC curve for reaching "adverse endpoints" Biochemical parameters better predicted length of hospital stay and adverse outcomes. A combined scoring system improved the sensitivity of prediction.