Abstract The CdSe nanoneedles were successfully grown by a green room temperature solution method. The preparation conditions induce a unilateral growth from base to tip of nanoneedle-like structures, despite the absence of any template. X-ray diffraction and scanning electron microscopy show that the CdSe nanoneedles crystallize in the wurtzite-structure with the growth direction along <100>. A photoluminescence peak with full width at half maximum of around 30nm could be obtained, which indicates a homogeneous and narrow size distribution for the CdSe nanoneedles.