Background: Antiphospholipid syndrome (APS) is an autoimmune multisystem disorder characterized by arterial, venous, or small vessel thromboembolic events and/or pregnancy morbidity in the presence of persistent antiphospholipid antibodies Objectives: To study the clinical and immunological profile of APS patients at a tertiary care centre Participants: All the APS patients attending rheumatology OPD clinic as well as CTD patients admitted under different divisions of Internal Medicine and department of obstetrics and gynecology and diagnosed as having APS. Study design: It was a hospital based observational study Methods: The diagnosis of APS was on the basis of characteristic clinical features and autoantibodies. Patients were classified as APS if they fulfilled international consensus statement update of the classification criteria for definite APS, and ACR/EULAR Criteria for associated Rheumatic disease in Secondary APS. RESULTS: Our study was an observational study of 124 patients. Most common clinical features were early fetal loss in 48(38.7%),late fetal loss in 57(45.6%),thrombocytopenia in 33(26.6%), DVT in 28(22.6%).Most common antibody was lupus anticoagulant 66(53.2%),anticardiolipin antibody 44(35.5%) and β2 glycoprotein antibody 33(26.6%). Conclusion: APS is a disorder characterized by a wide variety of clinical manifestations. There is a broad spectrum of disease among individuals with aPL, from asymptomatic to imminently life-threatening CAPS. Patients may exhibit clinical features suggesting APS but not fulfill the International Criteria for a ‘‘definite’’ diagnosis. SNAPS patients demonstrate typical idiopathic thromboses but aPL are not initially detected. Microangiopathic APS may present with isolated tissue and organ injury or as the overwhelming ‘‘thrombotic storm’’ observed in CAPS. Abbreviations: APS: Antiphospholipid Syndrome,aPL: Antiphopholipid Antibodies,SNAPS: Seronegative Antiphospholipid Syndrome,CAPS: Catastropic Antiphospholipid Syndrome,SLE: Systemic Lupus Erythematosus,MCTD: Mixed connective tissue disorders,UCTD: Undifferntiated connective tissue disorders,aCL: Anticardiolipin Antibody,LA: Lupus Anticoagulant,ANA: Anti-nuclear Antibodies,CRP: C-Reactive Protein,ESR: Erythocyte Sedimentation Rate,CBC: Complete Blood Count ,CTD: Connective Tissue Disorders ,ELISA: Enzyme-Linked Immunosorbent Assay