Objective: Many factors affect breastfeeding rates. One of these factors is the mother’s perception of insufficient milk. This study was conducted to determine the factors affecting lactating women’s perceptions of having insufficient milk and the foods they used to increase the breast milk. Methods: This descriptive study was conducted with 356 women. The data were collected using the “sociodemographic information form”, the “form for determining the foods used by women to increase breast milk”, and “perceived insufficient milk supply (PIMS)" scale. One-way analysis of variance, the independent samples t-test, the Bonferroni test, and Pearson correlation analysis were applied in the evaluation of the data. Results: The mean PIMS score was 42.39±7.48, and 80.3% of the women perceived their milk to be sufficient. A significant relationship was found between the mean PIMS score of the participants and employment status (p<0.000), time of first breastfeeding (p<0.000), milk being produced immediately after birth (p<0.000), and having enough milk to meet the needs of the baby (p<0.000). It was found that women consumed it and found it beneficial for increasing breast milk by consuming herbs: 30.6% used fennel, 12.6% linden; beverages: 71.3% used water, 50.6% compote, and 28.7% soups; foods: 31.2% used bulgur wheat, 24.2% fruit. Conclusion: It was observed that most mothers perceived their milk supply as sufficient. It was determined that PIMS score was affected by working status, time of milk coming in after birth, and breastfeeding status immediately after birth. It was determined that mothers consumed the most fennel, linden, parsley, water, compote, soup, fruit juice, bulgur pilaf, fruit, raisins, green vegetables and molasses to increase their milk supply.