Mammography is obviously useful for the early detection and diagnosis of breast diseases in women. However, it usually involves anxieties and pains. This paper aimed to explore effects of the communication robot on distress reduction in mammography. Nineteen healthy women participated in the examination. They were randomly assigned to either an experimental group (n = 9) or a control group (n = 10). The participants in the experimental group talked and played with a communication robot before mammography. PALRO (FUJISOFT Inc., Tokyo, Japan) was used as the communication robot, which was a chatty, comforting robot. PALRO can communicate with the human and has several specific applications such as dancing, singing and talking about knowledge of various things. Autonomic nervous activities were observed before and during mammography. Degrees of subjective pain associated with mammography were also assessed using a visual analogue scale (VAS). As a result, autonomic nervous activities between the experimental group and the control group were not significantly different. Unfortunately, the communication robot did not help to intensify parasympathetic nerve activities, which became dominant at rest or a relaxed state. On the other hand, the VAS scores for pain in the experimental group were significantly smaller than ones in the control group (p < 0.01). This result suggested that the communication robot was useful for relieving degrees of subjective pain associated with mammography. In conclusion, communication with a robot before mammography would yield positive emotions and it would be related to the pain alleviation during mammography.