The potential use of plasma-deposition techniques for the preparation of recognition coatings for mass sensors was investigated. Ethylenediamine and 4-vinylpyridine plasma-produced coatings and solution-deposited coatings from commercially available polyethyleneimine and poly(4-vinylpyridine) on quartz crystal microbalances (QCMs) were examined for the detection of acetic acid and other vapors. Freshly prepared QCM plasma-deposited recognition coatings from both ethylenediamine and 4-vinylpyridine were found to be very sensitive to acetic acid vapors. However the sensitivity decreased rapidly with time. Aging effects with solution deposited polymers films were noted as well. It was concluded that plasma-deposition of recognition coatings has great potential in the preparation of recognition coatings. In addition to well known advantages of the use of plasmas for surface film preparation or modification, the technique offers a one-step process of synthesizing and depositing high molecular weight films from volatile compounds not polymerizable by conventional means. A major disadvantage is that the chemical nature of the resulting coating is not easily predictable. However, careful choice of carrier gas and recognition film precursor can do much to simplify the design of effective recognition coatings.