General aim: this study aims to determine the prevalence of sensitization reaction on exposed and unexposed groups of workers at a latex factory. Specific aim: to determine the latex allergen sensitization reaction and factors such as atopy, age, sex, smoking, length of working, exposure concentration.Sample and method: the sample population consists of workers at a sphygmomanometer and condom factory who were, exposed and un-exposed to latex material at the factory. The number of sample was determined based on the two proportion formula.This study was a cross-sectional study using the Chi square test, Fisher test, Mann Whitney test, and Kruskal Wallis test.The results of the study and conclusion: The prevalence oj latex allergen sensitization reaction in the exposed group was 2.38%, while in the un-exposed group 3.33%. The correlation between exposed and un-exposed group to the latex allergen sensitization reaction (overall) was not significant (p=0.l8I), but if the correlation of each factor was calculated, the most significant correlation was between the negative latex allergen sensitization reaction with a strength of +2 or above (p=O.OJ4).In this study, atopy (p=0.000), exposed concentration (p=0.014), and smoking (p=0.018) are factors that were associated with latex allergen sensitization reaction. Workers at the condom factory were at higher risk than those at the sphygmomanometer factory, with a prevalence oj'7.14% and 2.31% respectively.