This secondary analysis was conducted to determine the relationship between test weights and days of breastfeeding. Test weights were performed with a scale (accurate to 2 grams) before and after feeding. Days of breastfeeding was measured by self-reporting. All test weights were interrelated and were associated with higher days of breastfeeding. Test weights at day 2 to 4 and at 2 weeks were not correlated significantly with either intention or self-efficacy at any time. However, 6-week test weights were correlated with intention at all 3 times, and self-efficacy at 6 weeks. Women with higher breastfeeding self-efficacy scores tended to report higher intention to breastfeed for 6 months.