A highly sensitive rapid Gas Chromatograph with mass spectrometer (GCMS) method has been developed and validated for the determination of genotoxic impurities, i.e Methyl N-Ethyl-N-Methylcarbamate, Ethyl N-Ethyl-NMethylcarbamate and N-Ethyl-N-Methylcarbamoyl chloride contents in Rivastigmine tartrate drug substance. The lower level of detection was achieved on Capillary GC column (DB-35, Fused silica capillary column; 30 m length; 0.32 mm internal diameter, coated with 35% phenyl and 65% dimethylpolysiloxane stationary phase of 0.5 mm film thickness with Electron Impact ionization (EI) in Selective Ion Monitoring (SIM) mode. The developed method was validated for specificity, linearity, accuracy and precision. The detection limits of Methyl N-Ethyl-NMethylcarbamate, Ethyl N-Ethyl-N-Methylcarbamate and N-Ethyl-N-Methylcarbamoyl chloride obtained were 2.0 μg/g each. The method was found to be linear in the range between 6 μg/g and 120 μg/g with correlation coefficient 0.9993, 0.9989 and 0.9988 respectively. The average recovery range obtained for these three impurities was between 97.3 % and 108.7%.