It has been suggested that one of the main factors contributing to the perception of esthetics is the position of the gingival tissues in the upper arch. The aim of this study was to evaluate the esthetic perception of dental students regarding different pictures of classical periodontal situations related to the gingival margin. This was an observational cross-sectional study involving 161 dental students. Five clinical situations defined by pictures from books were presented to the students. The cases included unchanged periodontium, gingival smile, uneven gingiva, localized gingival recession and generalized gingival recession. Esthetic perception was evaluated by a Visual Analogue Scale (VAS). The different situations were compared by One-way ANOVA, with Tukey test as post-hoc. The results showed statistically significant differences between groups (p < 0.05). The best esthetics was attributed to the periodontium without changes in shape (7.60 +/- 1.80), followed by gingival smile (6.92 +/- 2.34). The worst esthetic situation in this evaluation was the uneven gingiva (3.45 +/- 2.00). In the intermediate group are the gingival recessions. The perception of localized (5.19 +/- 1.91) and generalized (5.69 +/- 2.18) gingival recession did not differ significantly. This study concluded that different positions of the gingival tissues affect the esthetic perception of smile.