Objective: Family caregivers (FCs) of cancer patients are frequently seen as a barrier to honest communication with patients in Egypt. This study was conducted to investigate the attitude of FCs of cancer patients toward cancer diagnosis disclosure (CDD) and its determinants.; Methods: A structured interview was used to assess the preferences of 288 FCs regarding CDD.; Results: According to the FCs, 85% of patients were aware of their diagnosis. The majority (81%) of FCs preferred CDD to patients. In case they developed cancer, 92% of FCs wanted to know their diagnosis and 88% wanted to inform their families. In a univariate analysis, factors associated with FCs' negative attitude toward CDD to patients were as follows: patient's lower level of education (P = .001), patient's rural residence (P < .001), hematological malignancies (P < .001), FC's belief that the patient is unaware of diagnosis (P < .001), FC's unwillingness to know his/her own cancer diagnosis (P < .001), and FC's unwillingness to inform his/her family about his/her cancer diagnosis (P < .001). Only 2 factors predicted independently the negative attitude of FCs toward CDD, the FC's belief that the patient is unaware of diagnosis (P < .001), and the FC's unwillingness to know his/her own cancer diagnosis (P = .049).; Conclusions: The results suggest that the majority of FCs of Egyptian cancer patients prefer CDD to patients. The finding that the vast majority of FCs of aware patients preferred CDD suggests that the reaction of Egyptian patients to CDD is acceptable by FCs. Family caregivers with a negative attitude toward CDD may be reflecting their own fears.; Copyright © 2016 John Wiley & Sons, Ltd.