A 30-year-old female presenting with arterial occlusions of the lower limbs was discovered to have a markedly abnormal thrombin time and reptilase time. Further investigations revealed the presence of a qualitatively abnormal fibrinogen. Two other family members who were completely asymptomatic had similar defects. The abnormal fibrinogen has been characterized and found to be a new variant and as such designated fibrinogen 'Haifa'.