A study was conducted to investigate the degree to which both object familiarity and motivational factors influence infants' search behavior in an object permanence test. Infants' search behavior for an unfamiliar test object was compared with search behavior for (a) an experientially familiar object that each infant had played with daily for a week and (b) an attached object, such as a bottle, which the mother reported comforted the infant in times of stress. Thirty-six infants (15 males and 21 females) between 8 and 13 months of age were tested in three experimental conditions: unfamiliar object condition, familiar/object condition, and attached object condition. The Uzgiris-Hunt scale of object permanence was used to assess substages in the development of object permanence. Comparison between subjects' scores in the unfamiliar and familiar object conditions provided no evidence that object familiarity alone influenced test performance. Whether or not the infants' search behavior significantly increased for attached objects depended on which of two examiners administered the object permanence test. It is concluded that the results are best explained by motivational factors and that this has important implications for object permanence testing. (Author/MP)