Male chimpanzees at the Gombe National Park were twice seen to attack 'stranger' females and seize their infants. One infant was then killed and partially eaten: the other was 'rescued' and carried by three different males. Once several males were found eating a freshly killed 'stranger' infant. A similar event was observed in Uganda by Dr. Suzuki and Dr. Nishida reports an incident from the Mahali Mountains, Tanzania. A different kind of killing occurred at Gombe when a female and her daughter killed and ate three infants of other females of the same community during a 2-year period. There is evidence suggesting that other infants may have died in this way. The paper draws attention to puzzling aspects of infant killing and cannibalism in chimpanzees.