This review describes the developments of organic photovoltaic materials containing furan or benzo[1,2-b:4,5-b′]difuran (BDF) building blocks. Promising power conversion efficiencies above 6% have been achieved in the past two years for the BDF donor–acceptor polymers. Fundamentals of organic photovoltaics are briefly introduced at the beginning of this review. The uniqueness and advantages of BDF building block in semiconducting materials are discussed and compared with benzo[1,2-b:4,5-b′]dithiophene analogues.