There are individual differences in the frequency of chemotherapy-induced nausea and vomiting (CINV) in cancer patients. We investigated the individual variability in susceptibility to CINV with focus on both behavioral factors and genetic factors in Japanese cancer patients. We performed a prospective study to investigate the association between patient attributes (backgrounds and habits as well as gene polymorphisms) and anorexia, nausea, or vomiting in 55 Japanese cancer patients undergoing chemotherapy at Nagoya University Hospital. We found that gender (female), use of non-steroidal anti-inflammatory drugs, susceptibility to motion sickness, and anxiety were associated with the frequency of CINV. Gene polymorphisms of rs1076560 (dopamine D2 receptor gene), rs6766410 (serotonin 5-HT3C receptor gene) and rs4680 (catechol-O-methyltransferase gene) were also associated. Our data suggest that these attributes may thus be risk factors for CINV. Our results provide novel information that can be used to predict the incidence of CINV in Japanese patients undergoing chemotherapy; this can help provide a substantial improvement in supportive care for patients with different types of cancer.