Introduction: Haemophilia is X- linked congenital bleeding disorder with a frequency of about one in 10,000 births. Haemophilia is caused by deficiency of coagulation factor VIII (haemophilia A) or factor IX (haemophilia B) related to mutations of clotting factor gene. Objectives: To check effectiveness of various screening and confirmatory tests for diagnosis of haemophilia. Methods: Retrospective study of laboratory diagnosis of haemophilia was conducted in our haematology section of pathology department of Tertiary Care Teaching Centre from 1 August 2014 to 30 July 2016. Patients in the age group of 0 year to 55 years with factor VIII and factor IX level below 50% of normal were included in the study. Routine haematological tests like haemoglobin and platelet count and coagulation profile of patient for prothrombin time, activated partial prothrombin time, factor VIII and factor IX level were analysed. Results: Out of 122 cases, 97 cases were of haemophilia A while 25 cases were of haemophilia B. Haemoglobin count of patients ranged from6gm% to 14.2 gm%. Platelet count and PT (prothrombin time)of patients were within normal limits. APTT (Activated Partial Thromboplastin Time) was prolonged (41.6 sec. to 124 sec) in all patients. Factor VIII level was reduced (__ampersandsignlt;50%) in all patient of haemophilia A. Factor IX level was reduced (__ampersandsignlt;50%) in all patient of haemophilia B. Conclusion: Laboratory analysis of blood for haemoglobin, platelets, PT and APTT help to suspect the diagnosis. Diagnosis of haemophilia is confirmed by factor VIII assay for haemophilia A and factor IX assay for haemophilia B. Level of factor VII and IX also decide severity of disorder.