Objectives: To compare population-based sterilization rates between Latinas/os and non-Latinas/os sterilized under California's eugenics law.

Methods: We used data from 17 362 forms recommending institutionalized patients for sterilization between 1920 and 1945. We abstracted patient gender, age, and institution of residence into a data set. We extracted data on institution populations from US Census microdata from 1920, 1930, and 1940 and interpolated between census years. We used Spanish surnames to identify Latinas/os in the absence of data on race/ethnicity. We used Poisson regression with a random effect for each patient's institution of residence to estimate incidence rate ratios (IRRs) and compare sterilization rates between Latinas/os and non-Latinas/os, stratifying on gender and adjusting for differences in age and year of sterilization.

Results: Latino men were more likely to be sterilized than were non-Latino men (IRR = 1.23; 95% confidence interval [CI] = 1.15, 1.31), and Latina women experienced an even more disproportionate risk of sterilization relative to non-Latinas (IRR = 1.59; 95% CI = 1.48, 1.70).

Conclusions: Eugenic sterilization laws were disproportionately applied to Latina/o patients, particularly Latina women and girls. Understanding historical injustices in public health can inform contemporary public health practice.