Resulting from field work in all seasons 120 taxa are newly recorded for the island of Antikythera, among them 13 local or Aegean endemics. The total number of native plant taxa on the island is raised to 336. From the nearby islets Thimonies and Prassou, thus far unexplored botanically, 8 and 98 taxa, respectively, are recorded. Chorological and biological spectra of the total flora of the islands are given and discussed. A description of the vegetation of the area is added, including a vegetation map. The need for intensive exploration of the Greek island flora during all seasons is emphasized.