Objective To evaluate feeding styles of adolescent mothers and complementary feeding practices of their infants. Methods A cross-sectional study comparing a group of dyads of 50 adolescent mothers (ages 15 to 19) with 62 adult mothers (ages 24 to 44) and their infants (9 to 24 months) was performed. All mothers and infants were assisted by three basic health family units in the city of Recife, Brazil. Data were collected through a structured interview on socioeconomic conditions, maternal styles of feeding the child, and evaluation of infant feeding practices. The food styles were classified as responsive, authoritative, and passive, according to the adapted form of Carvalhaes, Perosa and Silveira of 2009. The frequency of food intake was calculated for six food groups (1. Bread and cereals; 2. Fruits and vegetables; 3. Meat, eggs, and beans; 4. Milk and dairy products; 5. Sugars, sweets, and fats; 6. Industrialized food). Children’s anthropometry and body mass index by age were classified into Z-score according to the World Health Organization Standard Curves, 2006. Results Adolescent mothers began complementary feeding more frequently before the seventh month (.=0,02), presented less responsive (.=0.04) and more authoritarian feeding styles (.=0.01), and their children received more foods with sugars, oils, and fats (.=0.02), and less meat, eggs, and beans (.=0.06) than the children of adult mothers. Conclusion Adolescent mothers adopt less responsive eating styles and offer more inadequate complementary feeding for their infants.