Objective: to investigate the effect the grandmother has on the breastfeeding mother and how it relates to the incidence and prevalence of breastfeeding. Materials and methods: A comprehensive database review was conducted in MEDLINEOVID, DIALNET and the COCHRANE LIBRARY. After analyzing the texts, eleven studies aimed directly at verifying the influence of grandmothers on the incidence and prevalence of breastfeeding in different contexts were selected. Results: The grandmother emerges as a source of support among the rural population (41 %). In the urban population, the grandmother appears among the three main factors (mother's intention to breast-feed or not, mother's decision on a feeding pattern for her child, and objective information on breastfeeding patterns), in a supporting role (94, 7%) and in a hindering role (26.7 %). As for the mother's decision on a feeding pattern for her children, 78 % reported having made the decision before pregnancy or in the first quarter. Living with the grandmother is positively associated with providing water or teas (PR in Cox regression with 95 % CI: 1.51 [1.10 to 2.09], p = 0.011). Conclusions: In the light of the review, the detracting or non-detracting influence exerted by the grandmother with respect to breastfeeding affects the three main factors. The detracting influence exerted by the grandmother's advice seems to be related to incorrect knowledge acquired more as part of the "bottle fed generation" rather than intentionality, and is susceptible to being modified through appropriate information, with favorable results on the feeding pattern.
