Mass spectra of methyl esters of three common drinking water chlorination by-products, bromodichloroacetic acid, dibromochloroacetic acid and tribromoacetic acid, are presented. The spectra are obtained in electron impact and chemical ionization modes, using a quadrupole mass spectrometer. Proposed fragment ion assignments are presented in detail. Fragment clusters were identified from their m/z values and confirmed with their relative isotope ratios. The detailed mass spectra presented are especially useful because standards for these drinking water contaminants are not yet commercially available.