EFSA received a mandate from the European Commission to assess the effectiveness of some of thecontrol measures against diseases included in the Category A list according to Regulation (EU) 2016/429on transmissible animal diseases (‘Animal Health Law’). This opinion belongs to a series of opinions wherethese control measures will be assessed, with this opinion covering the assessment of control measuresfor Highly Pathogenic Avian Influenza (HPAI). In this opinion, EFSA and the AHAW Panel of expertsreview the effectiveness of: (i) clinical and laboratory sampling procedures, (ii) monitoring period and (iii)the minimum radius of the protection and surveillance zone, and the minimum length of time themeasures should be applied in these zones. The general methodology used for this series of opinions hasbeen published elsewhere; nonetheless, specific details of the model used for the assessment of thelaboratory sampling procedures for HPAI are presented here. Here, also, the transmission kernels usedfor the assessment of the minimum radius of the protection and surveillance zones are shown. Severalscenarios for which these control measures had to be assessed were designed and agreed prior to thestart of the assessment. In summary, sampling procedures as described in the diagnostic manual forHPAI were considered efficient for gallinaceous poultry, whereas additional sampling is advised forAnseriformes. The monitoring period was assessed as effective, and it was demonstrated that thesurveillance zone comprises 95% of the infections from an affected establishment. Recommendationsprovided for each of the scenarios assessed aim to support the European Commission in the drafting offurther pieces of legislation, as well as for plausible ad hoc requests in relation to HPAI.