This paper discusses some of the major research and development issues for small wind turbines whose upper power limit we take arbitrarily as 50 kW. The basis for the comparison is the mature technology available for large turbines which has yet to be fully diffused downwards. After defining and categorising the important features of small turbines, the paper considers the major issues of blade aerodynamics, especially starting performance and materials and manufacturing methods. We conclude with a brief discussion of current developments in technology, which should increase the level of small turbine technology towards that of large machines.