The Sociocommunication Model of Infant Pain [Craig KD, Pillai Riddell R. Social influences, culture and ethnicity. In: Finley GA, McGrath PJ, editors. Pediatric pain: biological and social context, Seattle: IASP Press; 2003.] theorizes that maternal variables influence the pained infant and that the pained infant reciprocally influences maternal responses to the infant. The current analysis examines the relative predictive utility of maternal behavioral and psychosocial variables for both maternal judgments of her infant's pain and behavioral measures of infant pain, after infant factors have been controlled. A convenience sample of 75 mother-infant dyads was videotaped during a routine immunization in a pediatrician's office. Mothers were interviewed on the telephone, within two weeks, to complete a series of questionnaires. Infants were between the ages of 5 and 20 months. Infant pain was measured directly after the immunization using subjective maternal judgments. In addition, both maternal soothing behaviors and infant pain behaviors post-immunization were measured using objective coding systems. During the telephone interview, mothers were asked to recall infant pain levels for the day after the immunization and were also assessed for level of acculturative stress, perceived social support, general relationship style, feelings towards her infant and endorsed psychopathology. Regression analyses suggested that the role of maternal behavioral and psychosocial variables was highly dependent on the infant pain measure being predicted. These results imply that given the dependence of infants on their primary caregivers, quite often mothers, it is important to understand the dynamic influence of infants' behavior on maternal judgments of infants' pain and maternal psychosocial variables on infants' expression of pain.