The open access (OA) movement has exploded in the last few years. In 2016 we invited 1,896 researchers based in Spanish institutions to fill in a survey on their opinion, attitudes and practices towards OA. We analysed the 554 responses received from researchers in all fields of knowledge (29% response ratio). Most researchers are aware of OA outlets in their fields (86%) and believe OA is beneficial (76%). There isn't a clear position on the quality of OA journals among Spain-based researchers and there are differences between disciplines. Almost 70% of researchers have published at least one OA article in the last 5 years. Half of them had to pay article processing charges (APCs) that were covered with research funds.