This study examined the associations between infant and childhood growth and severe personality disorders. Among 4,689 men and 4,200 women of the Helsinki Birth Cohort Study 1934-1944, 81 men and 68 women had been hospitalized with an ICD (-8, -9, -10) diagnosis of personality disorder in adulthood. Among men, slower gain in BMI between birth and 6 months, faster gain in weight and BMI between 6 months and 1 year, and slower gains in them between 7 and 11 years of age predicted an increased risk of hospitalization for personality disorders. Thinness at 6 months and again at 11 years also showed significant association with personality disorders among men. Among women, slower gain in height between 2 and 7 years predicted hospitalization for personality disorders. Our findings show the importance of early growth as a vulnerability factor of personality disorders severe enough to justify hospitalization.