A prospective study of 32 normal, married primigravidas was conducted to determine the relationship between psychological factors in the third trimester of pregnancy and progress in two defined phases of labor. Data were analyzed for the total group and with five subjects deleted to control partially for the effect of medications. Psychological variables measured in pregnancy had significant correlations with variables measured at the onset of phase two labor. Conflict concerning the acceptance of pregnancy showed the most significant relationships to the phase two labor variables with correlations of .39 with anxiety. .59 with plasma epinephrine. –.70 and –.52 with two adjacent Montevideo units, and .58 with length of labor in phase two (3–10 cm cervical dilation). Other pregnancy variables which significantly correlated with the labor variables were identification of a motherhood role, history of psychological counseling or psychiatric treatment, the trait scale of the State-Trait Anxiety Inventory, and fears related to helplessness, pain, loss of control, and loss of self-esteem. Several psychological variables measured in pregnancy also correlated significantly with length of labor in phase three and type of delivery. The results demonstrate that specific psychological factors in pregnancy are predictive of progress in labor.