In this work, we presented a facile approach for the preparation of three-dimensional PbS nanoflowers, which was attributed to the coexistence of two types of amines with different-length alkyl chains and different steric hindrance. These monodisperse PbS nanoflowers showed small particle sizes (∼35 nm) and narrow size distribution (δ ≈ 9%). On the basis of these nanoflowers, we obtained a series of single-crystal hollow PbS nanostructures with tunable morphologies (including sphere, cuboctahedron, cube, and tube/rod) through elevating reaction temperature and prolonging growth time. It was further followed by a detailed discussion of the mechanism of morphology evolution, where the recrystallization and intraparticle ripening made contributions.