Although there are proposals in the literature for authoring mulsemedia (multiple sensorial media) applications with 2D content, there are no suitable solutions when it comes to 360°content. Moreover, little consensus on 360°mulsemedia authoring methodology exists. Aiming at filling this gap, we propose the concept of immersive authoring of 360°multisensory applications. Our proposal comprises an immersive 360°authoring environment to bring the author closer to the final user presentation environment. We implemented our proposal in AMUSEVR, a virtual-reality (VR) environment for authoring 360°m ulsemedia applications. We see it as an alternative or a possible complement to available 2D mulsemedia authoring tools. AMUSEVR provides creation and editing of interactive multiple sensorial media scenes by directly arranging objects in a 3D space using VR technology. Also, the tool allows users to run their applications through AMUSEVR viewer mode. We used the Goal Question Metric (GQM) approach to plan our tests and a group of users evaluated the tool with the SUS and UEQ questionnaires, obtaining a SUS score of 82.25 and an excellent UEQ benchmark, which are very promising results.