Objective To evaluate whether a country's Human Development Index (HDI) can help explain the differences in the country's breast cancer and gynecological cancer incidence and mortality rates in the Pan-American region. Study design Ecological analysis. Methods Pan-American region countries with publicly available data both in GLOBOCAN 2012 and the United Nations Development Report 2012 were included (n = 28). Incidence and mortality rates age-standardized per 100,000 were natural log-transformed for breast cancer, ovarian cancer, corpus uteri cancer, and cervical cancer. The mortality-to-incidence ratio (MIR) was calculated for each site. Pearson's correlation test and a simple linear regression were performed. Results The HDI showed a positive correlation with breast cancer and ovarian cancer incidence and mortality rates, respectively, and a negative correlation with cervical cancer incidence and mortality rates. The HDI and corpus uteri cancer showed no association. MIR and the HDI showed a negative correlation for all tumor types except ovarian cancer. An increment in 1 HDI unit leads to changes in cancer rates: in breast cancer incidence β = 4.03 (95% confidence interval [CI] 2.61; 5.45) P < 0.001, breast cancer mortality β = 1.76 (95% CI 0.32; 3.21) P = 0.019, and breast cancer-MIR β = −0.705 (95% CI 0.704; 0.706) P < 0.001; in cervical cancer incidence β = −3.28 (95% CI −4.78; −1.78) P < 0.001, cervical cancer mortality β = −4.63 (95% CI −6.10; −3.17) P < 0.001, and cervical cancer-MIR β = −1.35 (95% CI −1.83; −0.87) P < 0.001; in ovarian cancer incidence β = 3.26 (95% CI 1.78; 4.75) P < 0.001, ovarian cancer mortality β = 1.82 (95% CI 0.44; 3.20) P = 0.012, and ovarian cancer-MIR β = 5.10 (95% CI 3.22; 6.97) P < 0.001; in corpus uteri cancer incidence β = 2.37 (95% CI −0.33; 5.06) P = 0.83, corpus uteri cancer mortality β = 0.68 (95% CI −2.68; 2.82) P = 0.96, and corpus uteri cancer-MIR β = −2.30 (95% CI −3.19; −1.40) P < 0.001. Conclusions A country's HDI should be considered to understand disparities in breast cancer and gynecological cancer in the Pan-American region.