This quantitative survey attempts to explore factors that contribute to English as a foreign language (EFL) students' unwillingness to communicate across Indonesian secondary schools. To this end, an online questionnaire was distributed to the students via school Facebook pages and Twitter. A total of 158 students volunteered to participate, of which 122 were female, and 36 were male. The qualitative data were analyzed statistically using factor analysis, ANOVA, correlation, and regression. The study findings showed that there was significant correlation between the unwillingness to communicate scale (UCS) and its two factors, i.e. UCS1 and UCS2 were significant (r-UCS1 = .867, p < .01, r-UCS2 = .772, p < .01). These results indicate that students' unwillingness to communicate was highly influenced by whether or not students decided to stay away from the conversation or on the extent to which students valued the communication itself and vice versa. In addition, the regression analysis of the two variables, students' risk-taking to communicate and engagement in communication, revealed that none of the variables were perceived as predictors of the students' unwillingness to communicate [language class risk (LCR), β = -.198, t = -2.64, p = .009; and language class sociability (LCS), β = -.352, t = -4.69, p = .000].