Since 1977 a breeding group of Goeldi's monkey Callimico goeldii has been maintained at Brookfield Zoo. Between 1977 and 1997 there were 291 births of which 78 infants did not survive. Ninety per cent of the surviving infants have been parent-reared and hand-rearing is only carried out after maternal illness or rejection, or if injuries or other problems affect the infants. At Brookfield Zoo successful hand-rearing of Goeldi's monkey began in about 1979 and has been attempted for 66 (36.30) infants, 20 (10.10) of which survived and 46 (26.20) which did not. Changes to the hand-rearing procedures first outlined in 1982 are described and data are presented on birth mass and patterns of mass gain for successfully hand-reared infants. The circumstances relating to infants that did not survive hand-rearing are also documented.