The timing of having one's first child, in relation to the timing of other transitions into adulthood and to social functioning, was investigated based on the Finnish Jyvaskyla Longitudinal Study of Personality and Social Development, conducted from age 8 (173 females and 196 males) to 42. Results showed that in women, relatively early (less than 25 years) motherhood was associated with the early timing of all studied transitions (move from parental home, intimate relationship, education, full-time job); in men, early fatherhood was associated only with the early start of an intimate relationship. In women, but not in men, early parenthood was linked to a lower level of education, lower occupational status, an unstable career line, and heavier alcohol drinking. In the long run, early motherhood lessened its significance for occupational status. Furthermore, differences in education and drinking between women with early motherhood and women with late motherhood disappeared when school success was controlled for, and differences in career stability disappeared when low self-control was controlled for. (Contains 1 footnote and 5 tables.)