Remirea maritima has been widely used in the treatment of diarrhea, kidney disease, and high fever and for therapeutic purposes, such as an analgesic and anti-inflammatory. However, few scientific research studies on its medicinal properties have been reported. Purpose: The present study aimed to investigate the anticancer potential of aqueous extract (AE), 40% hydroalcoholic extracts (40HA) and 70% (70HA) from R. maritima in experimental models and to identify its phytochemical compounds. Methods: The chemical composition of AE, 40HA and 70HA was assessed by HPLC-DAD and ESI-IT-MS/MS . In vitro activity was determined on cultured tumor cell, NCI-H385N (Broncho-alveolar carcinoma), OVCAR- 8 (Ovarian carcinoma) and PC-3 M (prostate carcinoma) by the MTT assay, and the in vivo antitumor activity was assessed in Sarcoma 180-bearing mice. Toxicological parameters were also evaluated as well as the humoral immune response. Results: Among the aqueous and hydroalcoholic extracts of R. maritima , only 40HA showed in vitro bi- ological effect potential, presenting IC 50 values of 27.08, 46.62 and > 50 μg/ml for OVCAR-8, NCI-H385M and PC-3 M cells lines, respectively. Regarding chemical composition, a mixture of isovitexin-2 - O - β-D- glucopyranoside, vitexin-2 - O - β-D-glucopyranoside, luteolin-7- O -glucuronide and 1- O -(E)-caffeoyl- β-D- glucose were identified as the major phytochemical compounds of the extracts. In the in vivo study, the tumor inhibition rates were 57.16–62.57% at doses of 25 mg/kg and 50 mg/kg, respectively, and the tu- mor morphology presented increasing numbers of apoptotic cells. Additionally, 40HA also demonstrated significantly increased of OVA-specific total Ig. Conclusions: 40HA exhibited in vitro and in vivo anticancer properties without substantial toxicity that could be associated with its immunostimulating properties.