This study for the first time reports a quantitative analysis of phthalates and spatial distribution of phthalates in Lake Pontchartrain, Louisiana, USA using solid phase micro-extraction (SPME) coupled with gas chromatography mass spectroscopy (GC-MS). During 2008-2009, di-n-butylphthalate (DnBP) along with its congener (DiBP) and di(2-ethylhexyl) phthalate (DEHP) were detected in Lake Pontchartrain. Concentrations of these phthalates in the lake were monitored in different areas before and after the opening of the Bonnet Carré Spillway that occurred from April to May in 2008. The concentration of sigma3PAEs (DnBP, DiBP and DEHP) ranged from 0 to 20 microg/L in the surface water of the lake from March 2008 to June 2009. The distribution of the three phthalates varied with locations in the lake. An increase trend of sigma3PAEs was observed after the opening of the Bonnet Carré Spillway in the central lake area. The observed increase of the phthalates could be correlated to the opening of the spillway. The SPME followed by GC-MS employed in this study has been proved to be a rapid, sensitive and practical method to quantitatively analyse and evaluate phthalate concentrations in salt lake waters.