This study assessed how early motherhood influences maternal behavior and infant healthin Ethiopia. Data from the Ethiopian Demographic and Health Survey 2011 were used.Descriptive and Multinomial analysis were performed to observe the determinants of antenatalcare visits and birth weight. Cox regression model was employed for analyzing the risk of infantmortality. Findings clearly show that young maternal age at birth was associated with asignificantly lower number of ANC visits and increased the risk of infant mortality. However,there was no significant difference in the incidence of having babies with a low birth weight byage. Apart from maternal age at birth, education, wealth status, place of residence and ethnicityhad a stronger significant effect on outcome variables.In conclusion, this study demonstrated that young age at birth has an effect on utilizationof ANC service and infant health. For a favorable maternal behavior and infant health outcomewe strongly suggest that the following should be considered-: strong enforcement of minimumage at marriage abided by law, promoting young women’s education, and adequate andaffordable health care services in remote rural areas where health clinics are inaccessible.