Shape- and dopant-controlled magnetic semiconductor nanocrystals have been achieved by the thermolysis of nonpyrophoric and less reactive single molecular precursors under a monosurfactant system. Reaction parameters governing both the intrinsic crystalline phase and the growth regime (kinetic vs thermodynamic) are found to be important for the synthesis of various shapes of MnS nanocrystals that include cubes, spheres, 1-dimensional (1-D) monowires, and branched wires (bipods, tripods, and tetrapods). Obtained nanowires exhibit enhanced optical and magnetic properties compared to those of 0-D nanospheres. Proper choice of molecular precursors and kinetically driven low-temperature growth afford dopant controlled 1-D Cd1-xMnxS nanorods at high levels (up to similar to12%) of Mn, which is supported by repeated surface exchange experiments and X-ray diffraction (XRD) and electron paramagnetic resonance (EPR) analyses.