In this methodological, pilot study the usefulness of computer aided photograph analyses (CAPA) was tested for the demonstration of intraoral tissue changes, registered by standardized, clinical close-up (2:1) photography. Individual effects of tobacco on, a.o., the blood vessel supply of the oral mucosa were, thus, documented photographically every five minutes after cigarette smoking and snuff-dipping respectively in three healthy volunteers, aged 45, 35 and 30 years. In the same way the effects of nicotine, released from a 4mg Nicorette chewing gum (Leo), were recorded in all test persons. The clinical photographs were transformed into digital images and analysed by means of computer graphics (Supernova 24.1 and IBM-AT; ART 2 programme) for comparative investigations of the series of pictures. The methods employed facilitated the demonstration of even minor tissue changes in the original photographs. Standardized macrophotography of the oral mucosa and subsequent CAPA-procedures may be valuable tools in interdisciplinary research with the purpose to visualize, a.o. drug-induced, vascular changes. The digitized images may be used for statistical analyses. Further improvements of the CAPA-technique are in progress.