Scientific research in the Second World War has attracted the attention of numerous historians. However, while the development of Big Science projects such as atom bomb and radar have been explored in great detail, less attention has been paid to “Little Science”, ordinary scientific work conducted in various universities, research centres and laboratories in the course of the war. Little is also known about the mobilisation of science for the purposes of war in smaller countries such as Finland. As suggested by Mark Walker, this uneven coverage is both the result of, and the reason for the tacit assumption that focusing on large-scale projects would reveal the pattern the rest of science followed. Yet when looking at scientists working, say, in Finland during the Second World War, such assumption appears obsolete. Our paper is concerned with the development of science-based technology in Finland during the Second World War. On the one hand, the War severely hampered scientific research in Finland – simply because the majority of Finnish scientists were being called up to the Front. On the other hand, the war provided new openings for some individual scientists and fields considered relevant for the war effort. An exemplary case is the State Aircraft Factory where a group of able researchers were able to conduct development work in bearable material conditions. Another illustrative case is that of Alvar Wilska, a Finnish physiologist who was able to make valuable contributions to a variety of fields ranging from war surgery to the development of air surveillance. It is perhaps less surprising that the contributions of the Finnish scientists did not result in major scientific breakthroughs, let alone wonder weapons that could have turned the tide of the war for Finland. Rather, the need to overcome the wartime shortages and inconveniences gave rise to minor improvements in weapons and a range of technologies that may be termed “surrogates” –technologies that were vital to the war effort but that could not be purchased or had to be adapted to the local conditions. After the War, the experiences gained in such research laid the foundation for a successful production of civilian goods.