Methods Retrospective analysis of new events among primary-APS (pAPS) patients followed for up to 15 years in three medical centres in Israel. Results Among 312 primary-APS patients 143 (46%) had new thrombotic event classified to three patterns: (1) Arterialassociated with heart valve disease (OR 7.24, hypertension (OR 3,, elevated anti B2-GPI IgM (OR 1.04, 95% C.I. 0.996-1.08), arterial thrombosis at presentation (OR 1.74 CI95% 0.992-3.26) and older age (41 vs. 34 years, p<0.001). ( 2) Venouslinked with venous thrombosis at presentation (OR 12.9, 95% C.I. 5.27-31.6, p<0.001), heart valve disease (OR 9.81 CI95% 1.82-52.9, p=0.018), aGAPSS (OR 1.15 CI95% 1.02-1.29) and younger age (31 vs. 36.5 years, p=0.001); (3) Combined pattern -associated with heart valve disease (OR 40.5 95% C.I. 7.7-212) and pulmonary embolism (OR 7.47 95% C.I. 1.96-28.5). A 4th variant 'the Breakthrough pattern' defined by rethrombosis despite prophylactic therapy was observed in 100/ 143(70%) patients and linked with heart valve disease (OR 8. 95% C.I. 2.43-26.3), venous thrombosis at presentation (OR 2.61 95% C.I. 1.47-4.66), leg ulcers (OR 12.2, 95% C.I. 1.4-107), hypertension (OR 1.99, 95% C.I. 0.92-4.34) and higher aGAPSS (OR 1.08, 95% C.I. 0.99-1.18). Conclusion In this real life observation, re-thrombosis was common among pAPS patients including in those recommended to receive prophylactic therapy. Different patterns of recurrence were identified and linked with presenting symptoms, specific serological markers, APS-manifestations and comorbidities. Studies that will address interventions to prevent recurrences of APS related events are needed.