Objectives <p>Common maternal digestive symptoms, such as nausea, vomiting, and constipation during pregnancy, can impair pregnant women’s quality of life. The Mediterranean diet (MedDiet), characterized by a high consumption of olive oil, vegetables, fruits, legumes, and grains; moderate fish and dairy intake; and low meat consumption, could alleviate these symptoms. This study aims to study the prevalence of maternal digestive symptoms in the different pregnancy trimesters and to examine the association between baseline MedDiet adherence and the prevalence of maternal digestive symptoms during pregnancy.</p> Methods <p>A secondary analysis of the Walking Preg_Project trial was conducted in a cohort of adult Spanish pregnant women (<i>N</i> = 237) who provided data about MedDiet adherence and maternal digestive symptoms (nausea, vomiting, constipation) at baseline (12th ), 19^th, and 32nd Gestational Week (GW). MedDiet adherence was appraised through a 13-item questionnaire and categorized into low, medium, and high adherence. Digestive symptoms were assessed by the <i>Pregnancy Symptoms Inventory</i>. The association between baseline MedDiet adherence and maternal digestive symptoms was evaluated through adjusted multinomial analysis.</p> Results <p>Differences among MedDiet adherence categories were considerable during pregnancy. Some of the greatest decreases were observed in high adherence to MedDiet in comparison with low MedDiet adherence at 32nd GW vs. 19th GW for the prevalence of nausea (10.0% vs. 18.8%, <i>p</i> &lt; 0.001) and vomiting (5.0% vs. 8.7%, <i>p</i> &lt; 0.001). Constipation remained during pregnancy. There was no significant association between the baseline MedDiet adherence and maternal gastrointestinal symptoms.</p> Conclusion for Practice <p>Baseline adherence to the MedDiet was not proven to influence nausea, vomiting, and constipation during pregnancy. For all MedDiet adherence groups, nausea and vomiting prevalence decreased throughout pregnancy, but not constipation.</p>