To increase harmonization among European entomologists, the Aedes Invasive Mosquito species (AIM) COST Action (https://www.aedescost.eu) was initiated in 2018 including three major objectives: i) developing Pan-European networking and collaboration in monitoring and surveillance of AIM species; ii) increasing preparedness and capacity to fight against AIMs by triggering optimisation and innovation in AIM control strategies; iii) dissemination, customising and communicating the AIM-COST Action outcomes. AIM-COST Action aims to promote data sharing and harmonization. A particularly important objective is to ensure that vector sampling is consistent and compatible throughout Europe so an accurate continental picture of vector distributions can be obtained. For this, AIM?COST organised a training course in Cyprus in January 2020 on harmonising AIM surveillance across Europe. As a result of the course, trainers and trainees developed a protocol for surveillance of AIM species that can be applied across Europe. Forty-six teams from 24 countries (23 from Europe and one from North Africa) agreed on participating in the first-ever Pan-European surveillance of AIMs using a harmonized protocol (AIMSurv protocol; https://www.aedescost.eu/aimsurv). The AIMSurv protocol harmonized the sampling methods, frequency, minimum length of the sampling period and reporting. There were minimum requirements about the type of samples (i.e., eggs in oviposition traps) and recommended requirements for those teams having more resources (i.e., sampling of adults). Results from AIMSurv2020 are reported herein.