A solution-phase synthesis of monodisperse SnTe nanocrystals via the reaction of bis[bis(trimethylsilyl)amino]tin(II) with trioctylphosphine telluride in oleylamine is demonstrated. The obtained SnTe nanocrystals are single-crystalline particles with a cubic rock-salt crystal structure. The size of the SnTe nanocrystals can be precisely tuned in the range of 4.5-15 nm by tailoring the reaction temperature and stabilizer concentration. These SnTe nanocrystals exhibit size-tunable band gap energies of 0.38-0.8 eV. The narrow size-distributions allow assembling SnTe nanocrystals into 3-dimensional superlattices.