Objective: to design and validate a text messages database to promote breastfeeding. Materials and methods: quantitative research, instruments validation type done in three phases: (1) creation of text messages from documental analysis, (2) validation of content with experts, (3) comprehension tests with pregnant and maternal women. The analyzed information was done with SPSS version 22. Results: the final database had 96 text messages, submitted to the content validation phase with the participation of 13 experts. The internal consistency was “very high” with Cronbach Alfa of 0.93. The results of comprehension tests showed an adequate understanding of messages by pregnant and maternal women, Conclusions: the quantitative results showed through Cronbach Alfa, and comprehension tests administered to pregnant and maternal women, allowed to keep all the messages elaborated in phase 0 of the research and justify their adequate use for the promotion of breastfeeding.