13-year-old female twins presented one week apart with documented Mycoplasma pneumoniae respiratory infection. Each developed venous thrombosis/pulmonary emboli in association with transient self-limited para-infectious anti phospholipid antibodies. Comprehensive evaluation reveled no identifiable genetic prothrombotic variables. Both children recovered after receiving antibiotics and anti-coagulation therapy. Thrombotic complications associated with Mycoplasma pneumoniae infections are rare, particularly in children; the occurrence of this complication in identical twins has not been previously reported.