The Mg (11) 280.270 nm! Mg (I) 285.213 nm intensity ratio was used for the comparative study of the matrix effects using two inductively coupled plasma atomic emission spectrometers (ICP-AES) with different torch sizes, under robust and non-robust conditions. We observed that in the presence of a matrix, i.e., 5mg ml" Na, the values ofthe ratio obtained were around 7 and I2 for mini-torch and conventional torch ICP systems, respectively. It has also been observed that under robust conditions the matrix eH`ect on different analytes decreased considerably for both ICP systems. Influence of matrix effect, under robust conditions, on the intensity ratios of various ionic- to—atomic lines such as, Cd (ll) 226.502 nm! Cd (I) 228,802 nm, Cr (Il) 267.716 nm! Cr (I) 357.868 nm, Mg (II) 280.270 nm! Mg (I) 285.213 nm, Ni (II) 231.604 nm! Ni (1) 232.003 nm, Ni (II) 231.604 nm/ Ni (I) 232.138 nm, Pb (II) 220.353 nm! Pb (I) 216.999 nm, and Zn (II) 206.200 nm/ Zn (I) 213.857 nm has also been investigated and the ratios were found to vary similarly. It was concluded that tlte matrix effect due to 5 mg ml" Na could be minimized efficiently on a mini-torch ICP system under robust conditions and tlte residual effect may be due to the sample introduction system.