A standard additions method for calibrating the response of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) is assessed. Desolvated particles from an ultrasonic nebulizer and particles from an ablation cell are introduced simultaneously to a twin quadrupole ICPMS. Matrix-matched or pelletized solid standards are not required, and the solution standards are easily prepared. The transport of sample particles from the LA cell and of aerosol particles from the solution nebulizer must be measured. The relative accuracy for the analysis of steel reference materials is a few percent, which is comparable to that obtained with matched solid standards.