The masses of all stable isotopes in the range 10<=A<=30 have been measured using the large double-focusing mass spectrometer recently constructed at this laboratory. No serious discrepancies are found between the present results and other mass spectroscopic measurements except at Ne20. The masses calculated from nuclear reaction energies are, with the exception of F19, lower than the present results. The agreement between the Q-value masses and the present mass spectrometric results is not improved by changing the mass spectrometric secondary standard C12 to agree with the Q-value result or by making the same percentage change in all mass doublet values. Neither is the agreement improved by a change in either the calibration of the nuclear spectrometers or the mass-energy conversion factor. Three Q-values which are inconsistent with other Q-values and also with the mass spectrometric results were eliminated from the nuclear reaction data and the Q-value masses recalculated. The new masses are in better agreement with the mass spectrometric results, but are still, with the exception of F19, lower than the present mass spectrometric values.