Cancer is a disorder of the female reproductive system, kinds of cancers that are often experienced by women are breast cancer, cervical cancer, colorectal cancer, and ovarian cancer. There were 21,290 incidents of ovarian cancer, 14,180 died and accounted for 2.4% of all cancer-induced mortality. The aim of this research is to know the difference of menarche age in patient with breast cancer and ovarian cancer. The type of this research is quantitative research and the research design used is comparative. The research subjects were female reproductive cancer patients with a population of 1206 female patients and using systematic random sampling which obtained a sample of 300 female reproductive cancers. The type of data used is secondary data taken from medical records. The data analysis uses Independent t test. The results showed that the average age of menarche in breast cancer patients is at menarche age of 11.15 years old (11 years 1 month 24 days old) and the average age of menarche in ovarian cancer patients is at menarche age of 11.39 years old (11 years 4 months 20 day old). The statistic test results showed that menarche age patients with breast cancer have p-value = 0,001 and OR = 4,917 and age menarche patients with ovarian cancer have p-value = 0.007 and OR = 2.27. Whereas the independent t-test analysis found p-value = 0.145 which means there was no age difference between patients with breast cancer and ovarian cancer.