Open access (OA) is a global movement to make research results widely available by removing price and permission barriers. OA infrastructure is necessary for implementing open access and open science in any country. The aim of the present paper is twofold: (i) to give a description of the Greek OA infrastructure with emphasis on academic repositories and OA journals, and (ii) to examined the OA availability of publications authored by Greek researchers and published in international journals. Results indicated that Open access infrastructures in Greece have been steadily improving over the past years, with 28 out of 36 HEIs running their own IR and 116 OA journals being published. The OA availability of the literature produced by Greek researchers is similar to that found in other studies and falls within the range that has been reported for European countries. Although numbers seem rather satisfactory, there are a number of challenges that have to be addressed at both the infrastructural and the policy level, the most important being the implementation of national open policies and funders mandates.