The purpose of this study is to systematically assess the level and spectral distribution of low frequency (LF) sounds in dwellings. Measurements of broad and narrow band sound levels have been made in 36 Dutch dwellings in 1998. In 19 dwellings there were complaints about LF noise, in 17 others no complaints had been reported. According to measured broad band and spectral levels complainants' dwellings can be divided into three categories with 'considerable', 'some' and 'no' LF sound. Measured levels and scores on proposed LF noise criteria in complainants' dwellings as a group however are not significantly different from dwellings without complaints. In cases' dwellings more narrow band LF components are present, but on average at a lower level compared to controls' dwellings.