A prospective cross sectional study of adverse drug reaction cases presenting at Medical and Dermatological wards of TUTH from April 2007 to March 2008 were studied. All suspected allergic reactions to systemic drugs was collected during one year period. All the patients were followed up till in wards and outcome was documented.  Both genders of 14 years and above of drug reactions were included in the study. The data were analyzed by using SPSS software.Out of 3366 Cases that were admitted in Medical and Dermatological wards, 0.9 % was Adverse Drug Reaction cases. The female male ratio was 1.3:1. The adults aged 31-50 years (40%) comprised the most cases. Most of the cases presented with cutaneous manifestations (60%). Maculopapular rash is the commonest cutaneous manifestations (20%). Most of the drugs reactions are type B (67%). Antimicrobials are common group of drugs implicated in ADRs (43%).Ciprofloxacin is the commonest antimicrobials involved. There were three cases associated with predisposing factors for ADR: HIV, SLE, and COPD. All the hospitalized patients of ADR managed by medical treatment and there was no sequelae of such reaction as well. All the patients have no previous history of drug allergy. Most Patients stayed at hospital for 4-7 days (40%).All the ADR cases were severe and one case of suspected antiretroviral associated ADR was found fatal.All the cases were severe and one patient died of suspected ADR during the study.