Perceived social support during gestation is important for perinatal mental health. However, little is known about these variables in the Colombian population. To compare perceived social support with sociodemographic and gynaeco-obstetric variables and positive affect in pregnant women in Santa Marta, Colombia. Forty women between 19 and 41 years of age (M=26.48; SD=5.03), in their third trimester of pregnancy and beneficiaries of a program to promote exclusive breastfeeding, participated. The participants filled out a sociodemographic and gynaeco-obstetric form, the Multidimensional Scale of Perceived Social Support (MSPSS) (a=0.88), and a subscale of the Positive and Negative Affect Schedule (PANAS) (a=0.82). The Mann-Whitney U test was used for comparative statistical analyses. Ethical guidelines for human research were followed. 67% of the participants belonged to a low socioeconomic status, 87.5% had a partner, 67.5% had a higher education, 42.5% were employed, and 47.5% were new mothers. Women of higher socioeconomic status perceived greater social support from their friends (p = 0.01). Family social support was significantly higher in first-time mothers (p=0.01) and mothers who reported higher positive affect (p = 0.03). Finally, social support from significant others was higher when it was the woman's first pregnancy (p=0.02). Significant differences were found in some dimensions of perceived social support according to socioeconomic status, being a first-time mother, and positive affect. Further studies with larger sample sizes are recommended.