Illness perception influences health and illness behaviors. This study was designed to estimate illness perception differences between Russian-speaking and Hebrew-speaking Israeli oncology patients. Changes in illness perception associated with time spent in Israel among Russian-speaking patients were also evaluated. Additionally, we evaluated differences in illness perception of patients exposed to Chernobyl’s consequences. A total of 144 oncology patients (77 Hebrew-speaking, 67 Russian-speaking) completed personal data questionnaires and The illness perception questionnaire revised, translated into Russian for this study. Significantly more Russian-speaking oncology patients perceived their illness as chronic and having negative consequences on life (p < .01). Russian-speaking oncology patients tend to have a more negative perception of cancer compared to Hebrew-speaking patients. Time spent in Israel may create more positive perceptions of cancer among these patients. No illness perception differences were found concerning Chernobyl consequences.