Thrombotic thrombocytopenic purpura (TTP) is an acute, life threatening disorder. The mainstay of treatment is plasma exchange (PEX) as a source of ADAMTS 13. In the UK, 20–25% of all plasma consumed is in patients with TTP. In our protocol (up until 31st December 2005) apheresis was initially with cryosupernatant (National Blood Service, UK) unless patients had a previous severe allergic reaction or refractory disease. Apheresis therefore continued with Solvent-Detergent Fresh Frozen Plasma (S/D FFP) Octaplas, (Octapharma, Vienna Austria) virally inactivated plasma, available throughout Europe. We reviewed 50 acute TTP episodes involving 32 patients. Thirteen episodes used cryosupernatant only and in 15 episodes, treatment started with cryosupernatant and changed to Octaplas. The reasons for changing were refractory disease in 2 episodes and major or recurrent allergic reactions to cryosupernatant in 13 cases. Once Octaplas had been used, it was continued on further admissions. In 22 episodes, Octaplas was used exclusively; in 4 cases as physicians choice and in the remaining due to previous reactions to cryosupernatant. The total volume of cryosupernatant used was 508250mls, 27.6% of all plasma; total volume of Octaplas was 1327600mls, 72.4% of all plasma. Citrate mediated reactions associated with symptomatic hypocalcaemia during apheresis were present in 11% of Octaplas and 20% of cryosupernatant. Acute or delayed urticarial or allergic reactions were noted in 5% of Octaplas and 10% cryosupernatant procedures. A particular complication of apheresis is central line infection. There were 21 line infections and in 43% of cases the infection was associated with a reduction in platelet count < 150 × 109/L. In all 50 episodes, the only documented thrombosis was a superficial non central vein in a patient who had received Octaplas. Prevention of venous thrombosis is by use of thromboembolic stockings, low dose aspirin and low molecular weight heparin in patients when platelet counts >50 × 109/L. In episodes receiving only cryosupernatant or Octaplas, there was no significant difference in the median number of PEX to remission, 7(3–14) and 8.5 (5–30) respectively. Baseline viral screen in all episodes was negative after discharge following an acute TTP episode. In conclusion: cryosupernatant and S/D FFP (Octaplas) appear equally efficacious. However, the risk of allergic/urticarial reactions was twice as common with cryosupernatant, as were citrate reactions. Milder allergic reactions to cryosupernatant are possibly higher, but may have been treated with antihistamines and data not recorded. There was no documented viral transmission with either product.