OBJECTIVE To investigate the association of sociodemographic, obstetrical and psychosocial factors with fine and gross motor developmental delay in preterm and term infants, in the age group of three months and one day to twelve months and twenty-nine days. METHODS The term and preterm infants were evaluated by the Denver II Test for fine and gross motor skills, investigated in three phases: 165 infants in phase 1 (3 months and 1 day to 4 months and 29 days), 130 infants in stage 2 (8 months and 1 day to 9 months and 29 days) and 102 infants in phase 3 (11 months and 1 day to 12 months and 29 days). Sociodemographic, obstetrical and psychosocial data were obtained through an initial interview with family members and the psychic risk assessment through the Child Development Risk Indicators and PREAUT protocols. Statistical analysis was performed using the logistic regression model. RESULTS Significant factors in the association with fine and gross motor delay were: maternal gestational and obstetric history (planned pregnancy, type of delivery, number of prenatal consultations, use of medication and gestational intercurrence), features and biological risks of the baby (gender, mechanical ventilation, feeding difficulty), sociodemographic factors (career and level of maternal schooling, number of children and people in the house) and psychosocial issues concerning to the family routine participation and presence of psychic risk. CONCLUSIONS There was a significant association between motor development delay of the infants, environmental and biological variables, with emphasis on psychic risk.