This paper presents new physical model experiments on tsunamis generated by landslides at the coast of a conical island. The experiments have been carried out in a large wave tank; the radius of the island coastline and the falling height of the landslide have been varied during the experimental campaign. The landslide is reproduced by a solid body shaped as a half of an ellipsoid. Tsunami runup is measured using special wave gauges; a detailed analysis of the runup along the coastline is presented, with special attention to the role of each wave in the packet and to the evolution of the envelope of the first group of waves.