This study aimed to evaluate the assessment of attractiveness of standardized changes in incisor proportions. Two original photographs, showing the maxillary anterior teeth in the frame of a smile, were computer-manipulated. From the so-produced symmetrical 'golden standard' images, two sets were constructed. Each set contained one golden standard image and seven images with different standardized changes concerning (i) width-to-length ratios of the central incisors (60-96%) and (ii) tooth-to-tooth proportions between the widths of lateral and central incisors (43-87%). The judges, consisting of three groups of individuals (24 dentists, 24 medical students, and 179 patients), ranked each photo set for attractiveness on a visual analogue scale. The width-to-length ratios were assessed as most attractive within a range of 75-85% (medical students, patients) or 75-80% (dentists), respectively. The tooth-to-tooth proportions showed the best results concerning attractive appearance within a range of 50-74% (medical students, patients) or 56-68% (dentists), respectively. No significant differences between the participant groups were found except for some extreme variations. It was concluded that a most attractive 'golden range' could be identified for both the width-to-length ratios and the tooth-to-tooth proportions of the maxillary incisors.