Stimulated emission in nineteen np-ns and np-(n-2)d transitions in K vapour was observed by optically pumping the np states with the second harmonic of a pulsed dye laser. The observed output wavelengths range from about 10 mu m to above 100 mu m. Wavelength measurements of the np-(n-2)d emissions can provide accurate unambiguous determinations of d-level energies. For the cases n=7 and n=8 stimulated Raman emission was observed at small detunings of the pump beam from the np resonance lines.