In this study a round robin analysis of 10 leachate samples was conducted by 32 laboratories in the United States and Canada. Samples were analyzed for up to 28 parameters, including physical parameters (ph, oxidation reduction potential, conductivity, turbidity, and residue), organics (chemical oxygen demand, total organic carbon, organic nitrogen, and free volatile fatty acids), anions (sulfate, phosphate, chloride, nitrate, and bicarbonate), and cations (alkali metals, alkaline earth metals, transition metals, and heavy metals). It was noted that the overall coefficients of variation ranged from 32% for the chemical oxygen demand to 210% for the cadmium determination. Significant differences were noted between results from colorimetric methods and titrimetric and physical methods. The average recovery for spiked parameters in one leachate sample was 81% but varied widely for individual parameters. Results obtained using automated methods commonly deviated from those of other methods. Recommendations were made for selection of the most applicable method for analysis of each parameter. The usage of the standard addition technique is required in each laboratory to determine the matrix depression or enhancement for each type of leachate sample.