A spectrometer system consisting of a quartz acousto-optic tunable filter (AOTF) and an echelle grating has been assembled and tested for ICP-AES continuous emission monitoring of heavy metal and actinide elements in stack exhaust offgases introduced into an air plasma. The AOTF is a rapidly tunable bandpass filter that is used to select a small wavelength range (0. 1 to 0.6 am) of optical emission from the air plasma; the echelle grating provides high dispersion, yielding a spectral resolution of approximately 0.004 to 0.008 nm from 200 to 425 nm. The AOTF-echelle spectrometer, equipped with a photodiode array or CCD, provides rapid sequential multielement analysis capabilities. It is much more compact and portable than commercial ICP-AES echelle spectrometers, allowing use ofthe system in field and on-line process monitoring applications. Data will be presented that detail the resolution, detection limits, capabilities, and performance of the AOTFechelle spectrometer for continuous emission monitoring of heavy metals (As, Be, Cd, Cr, Hg, and Pb) and actinides (including U isotopes). The potential use of the AOTF-echelle spectrometer with other emission sources and for other monitoring applications will be discussed.