QuaSAR implements a suite of tools for QC, analysis and visualization of data from quantitative MRM-MS experiments including assay configuration, calibration curves and new sample analysis. For every monitored peptide the module provides statistical measures such as, coefficient of variation (CV), regression slope and intercept (with confidence intervals), interference detection, and limits of detection (LOD) and quantification (LOQ). It also provides succinct visual summaries of various results including reproducibility, interferences and detection limits. Statistics and visualization are integrated to enable effective data interpretation, understanding and insight.