This research examined experimentally the effects of lighting colors and types of background music on conversational behavior at a cafe. When each table was occupied by same sex friends in the laboratory assumed as a cafe, the effect of the background music on their behavior was strong, but the effect of the lighting colors was weak. That is, when the tempo of the background music was fast there was a tendency for eye contact, the amount of conversation, and the conversational volume to increase. The lighting colors were important in regard to providing sufficient illumination for conversation partners to see each other's faces. Ease of talking was affected both by lighting colors and background music. The evaluation was more favorable with the use of general white lighting and with background music of an intermediate tempo, such as bossa nova and ballad style music.