The objective of this study was to confirm the risk factors (RF) for low birth-weight (LBW) and suggest new risk factors, which were analyzed separately and together, in order to define a program to be coordinated by family doctors to reduce the frequency of this problem. For this purpose, a retrospective cross-sectional survey was carried out with 57 cases (mothers who had had LBW babies) and 58 controls (mothers who had not had LBW babies). In addition, data were obtained from the prenatal records of mothers who received care at family doctors' offices and at the clinica in the Plaza de la Habana Area. Estimates were made of the relative risk and the percentage attributable risk of 107 hypothetical RF for LBW from a clinical-epidemiological and social standpoint. One-way analysis of variance, the chi-square test, multiple linear regression, and logistic regression were used to analyze the results, which suggested the following RF for LBW: family dysfunction, family crisis, lack of spousal support, extended family, failure to attend prenatal group sessions for pregnant women, and failure to receive education on how to prevent LBW. The multifactorial risk profile was the following: risk of [corrected] intrauterine growth retardation, family dysfunction, threat of preterm delivery, coffee-drinking, attendance at fewer than 11 prenatal checkups, and failure to attend prenatal group sessions for pregnant women. The variables excluded from the model were: low weight-for-height, lack of spousal support, smoking more than 10 cigarettes a day, and family history of LBW. The findings confirmed 10 of the suspected risk factors for LBW in Cuba and nine of those described in the international literature. Maternal age, spontaneous abortion, and alcohol consumption were not confirmed. Six RF for LBW preventable by the family doctor through his/her actions at the family and community level are identified, as is a multifactorial profile of six RF for LBW. On the basis of these results, proposals are made in regard to programming priorities and the implementation of strategies aimed at preventing LBW, and it is recommended that the study be continued with a larger sample.