The dependence of electronic states on the length and diameter of CdSe quantum rods is investigated using semiempirical pseudopotential calculations. Energy levels cross as the aspect ratio increases due to their different dependence on length. The crossover between the highest occupied levels leads to a transition from plane-polarized to linearly polarized light emission at aspect ratio ca: 1.3. Further increasing aspect ratio results in levels with similar symmetry converging and forming "bands". This calculation demonstrates the transition of electronic structure from zero-dimensional quantum dots to one-dimensional quantum wires.