Cavitation in atomizing orifices remains a consistent design problem in many modern engineering applications, and few analytical or numerical tools exist for its prediction. Visualization of cavitation in slot orifices at pressures up to 5 atm is reported. Slots with a minimum dimension ranging from 0.127 to 1.525 mm are studied. The incipient and desinent cavitation pressures are found for a variety of slot sizes. The extent of cavitation within the orifice as a function of cavitation number is also established for these slots. The liquid-vapor interface varies dramatically with slot geometry and local surface conditions at the inlet corner. Cavitation in certain sized orifices is observed to experience a complex, and apparently cyclical, growth and disintegration process. This lends to the conclusion that the constant contraction coefficient assumed by previous works is in error. The growth cycle is examined and discussed for one such slot geometry.