Haloacetic acids are disinfection byproducts of the chlorination of drinking water. This paper presents the analysis of all nine chloro and bromohaloacetic acids (HAA9) at the submicrogram per liter level by microextraction with detection by electrospray-mass spectrometry. The haloacetic acids are extracted from acidified water through a microscale liquid-liquid extraction. Perfluoroheptanoic acid is added to the extracts, and the haloacetic acids are detected with electrospray-mass spectrometry. Confidence in the selective quantification of the haloacetic acids is achieved by observing the stable association complexes that are formed between the haloacetic acids and perfluoroheptanoic acid. The method detection limits for the haloacetic acids are less than 1 microg L(-1), depending on the haloacetic acid. Standard addition is used to quantify the haloacetic acids in several water matrixes.