Background and Objectives—Breast milk feeding and solid food introduction can influence infant growth, but are rarely examined together. The objectives were: describe relationships between feeding practices, feeding practices and weight gain, and how the relationship of breast milk feeding and growth may change when breastfed infants start solid foods before 6 months. Methods—Data was analyzed on 438 infants from the Moms2Moms Study (2011–2012, Ohio), using multivariable linear and logistic regression models to explore each of the relationships. Results—For each additional month of breast milk feeding, solid food introduction was delayed by 1.32 days (95% CI: 0.11 to 2.53) and average weight gain per month decreased by 5.05 grams (95% CI: 7.39 to 2.17). There was no association between solid food introduction and growth. Conclusions—Longer breastfeeding duration was associated with slower growth regardless of solid food introduction. Age at solid food introduction was not associated with growth.