ObjectivesTo analyse post-tonsillectomy haemorrhage (PTH) rates related to technique for dissection and haemostasis. Study DesignRegister study from the National Tonsil Surgery Register in Sweden (NTSRS). MethodsAll patients, subjected to tonsillectomy (TE) without adenoidectomy from 1 March 2009 to 26 April 2013, were included in the study. The surgeon reports data about technique and early PTH, while late PTH is reported by the patient in a questionnaire 30days after surgery. Results15734 patients with complete data concerning technique for dissection and for haemostasis were identified in the NTSRS. Techniques used were cold steel dissection with uni- or bipolar diathermy haemostasis (65.3%), diathermy scissors (15.7%), coblation (9.1%), cold steel dissection with cold haemostasis (7.4%) and ultrascision (2.5%). Early and late PTH were reported in 3.2% and 9.4% of the cases, respectively, and return to theatre (RTT) in 2.7%. The rates for PTH and RTT related to technique were analysed. Compared with cold dissection+ cold haemostasis, late PTH rate was 2.8 times higher after cold dissection + hot haemostasis, 3.2 times higher after coblation, 4.3 times higher after diathermy scissors and 5.6 times higher after ultrascision. The risk for RTT was higher for all hot techniques except for coblation, while ultrascision resulted in a lower risk for early PTH. ConclusionsAll hot techniques resulted in a higher risk for late PTH compared with cold steel dissection +cold haemostasis. The risk for RTT was higher for all hot techniques except for coblation, while ultrascision resulted in a lower risk for early PTH. An early PTH was associated with an increased risk for late PTH.