A short-term psychologic intervention based on the technique of hypnotic relaxation has proven effective in causing a prolongation of pregnancy in cases of premature labor. This finding raises questions of practical and theoretical nature. One practical question is whether this treatment procedure would also be effective with other women suffering from premature labor, for instance, women with multiple pregnancies or after premature rupture of the membranes. Another question is whether the hypnotic-relaxation technique described could be effective in preventing premature labor in women known to be at risk. Such a prevention program might be carried out in groups and thus be economically feasible. An important theoretical question concerns the examination of the different elements in the treatment package which might be responsible for the effect achieved. Such examination would lead to a better understanding of the interaction between psychologic and physiologic variables and might eventually lead to the construction of more effective interventions.