Moral hypocrisy is prevalent and the presence of a stranger and his/her moral or hypocritical behavior might affect an individual’s moral hypocrisy. Therefore, based on a donation situation, we used experimental paradigms to explore the effects of a stranger’ presence and his/her moral or hypocritical behavior on an individual’s moral hypocrisy. In the pilot study, we developed an online scenario-based questionnaire to identify whether the amount of donation would be affected by the total amount an individual had. A total of 46 university students (15 boys, Mage = 21.02, SD = 1.06) were asked to expect how much they would donate if they had 50 and 20 yuan, respectively. According to the results, the proportions of donation were equal (50 yuan: M = 0.32, SD = 0.24; 20 yuan: M = 0.32, SD = 0.33; t = 0.13, df = 45, p = 0.900) between the two conditions. Therefore, we created the indicator of moral hypocrisy by subtracting the proportion of donation an individual donated (20 yuan in total) from the proportion one expected beforehand (50 yuan in total). In Study 1, a total of 60 university students (7 boys, Mage = 20.31, SD = 1.81) were recruited and were randomly assigned to “no stranger” or “with stranger” group. The participants had expected their amounts of donation before they got into the experiment room and then their donation behaviors (i.e., the amounts of money they actually donated) were measured after they finished a filler survey. Results showed that, the proportions participants donated were both significantly lower than that they claimed in the two groups (“no stranger” group: t = 4.54, df = 29, p < 0.001, d = 1.05, 1-β = 0.97; “with stranger” group: t = 6.35, df = 29, p < 0.001, d = 1.17, 1-β = 0.99), and the degrees of moral hypocrisy were the same (t = 0.42, df = 58, p = 0.677). It indicated that a stranger’s presence could not inhibit moral hypocrisy. In Study 2, a total of 60 university students (12 boys, Mage = 20.28, SD = 1.24) were recruited and were randomly assigned to “moral stranger” or “hypocritical stranger” group. The participants had expected the amounts of donation before they got into the experiment room and then their donation behaviors were measured after they finished a filler survey. Results showed that, in “moral stranger” group, the proportions participants actually donated were the same as that they claimed beforehand (t = 0.12, df = 29, p = 0.903), while in “hypocritical stranger” group, the proportions participants actually donated were significantly lower than that they claimed beforehand (t = 6.39, df = 29, p < 0.001, d = 1.60, 1-β = 1.00). It indicated that a stranger’s moral behavior could inhibit moral hypocrisy, while his/her hypocritical behavior had no effect. Overall, findings in the present study suggested that a stranger’s presence and as well as his/her hypocritical behavior could not inhibit an individual’s moral hypocrisy, while his/her moral behavior could inhibit another one’s moral hypocrisy.