The role of informal caregiver of cancer patients is considered a situation of chronic stress that could have impact on cognitive functioning. Our aim was to evaluate differences in perceived stress, subjective memory complaints, self-esteem, and resilience between caregivers and non-caregivers, as well as the possible mediational role of burden in caregivers. The sample was composed of 60 participants divided into two groups: (1) Primary informal caregivers of a relative with cancer (CCG) (n = 34); and (2) non-caregiver control subjects (Non-CG) (n = 26). All participants were evaluated through a battery of tests: Socio-demographic questionnaire, subjective memory complaints questionnaire (MFE-30), Rosenberg Self-Esteem Scale, resilience (CD-RISC-10), and perceived stress scale (PSS). The CCG group also completed the Zarit burden interview. Results indicated that CCG displayed higher scores than Non-CG in MFE-30 (p = 0.000) and PSS (p = 0.005). In the CCG group, Pearson correlations indicated that PSS showed a negative relationship with resilience (p = 0.000) and self-esteem (p = 0.002) and positive correlation with caregiver’s burden (p = 0.015). In conclusion, CCG displayed higher number of subjective memory complaints and higher perceived stress than Non-CG, whereas no significant differences were obtained on self-esteem and resilience. These results could aid in designing new intervention strategies aimed to diminish stress, burden, or cognitive effects in informal caregivers of cancer patients.