This study examined the relationship between maternal stress, changes in stress, specific stressors, and social support and quality of mother-infant attachment. Life stress of 132 mothers was assessed prenatally and when the child was 13 months old. The mothers' social support and the quality of infant-mother attachment were also measured at the child's 13th month, the latter by means of the Ainsworth Strange Situation procedure. Results indicated that high stress at 13 months, and an increase in stress from the prenatal period to 13 months, were associated with infants' anxious-resistant attachment in the strange situation. Partner stress, and stress related to changes in family relationships, differed significantly depending on attachment classification in the strange situation. Among mothers who reported low social support, there were no significant differences between the level of stress of mothers whose infants exhibited anxious-resistant attachment in the strange situation, and the stress of mothers whose infants exhibited anxious-avoidant or secure attachment. Eight references are cited. (BC)