Background: Phyllodes tumor (PT) is a rare tumor of the breast, which may occur during pregnancy or lactation. Several studies have reviewed and discussed PT occurring in pregnancy, gathering up to 14 patients. We performed a thorough systematic review of the literature in an attempt to find all reported cases, and identify their common characteristics. Methods: We searched Google scholar, PubMed, Ovid Medline, Scopus and ClinicalTrials.gov with several relevant combinations of keywords, looking for texts or abstracts without any date or language limitations, but using only English keywords. The existing literature only consisted of case reports and series; therefore any paper including one or several cases of PT presenting during pregnancy or breastfeeding was recognized as eligible. Articles with vague description of the tumor which made the diagnosis uncertain, and those lacking data about the tumor and management data were excluded. We contacted authors for more details in cases with incomplete information. Results: After excluding those with very deficient data, we included 37 studies, counting 43 cases. The mean age of the patients was 31 years (21-43 years). Some features were different from usual PT: bilaterality (16.2%), large size (14.2 ± 8.6 cm), rapid enlargement (79.5%), and rate of malignancy (60.5%). Conclusion: Our findings show high rates of bilaterality, large size, rapid growth, and malignant pathology in the reported gestational PTs.