Objective. To conduct a formative evaluation of a proposed mobile health (mHealth) program designed to educate caregivers about management of common childhood illnesses. Methods. A cluster-randomized sample (n = 220) of mothers in Cono Norte, Arequipa, Peru with at least one child under five completed an iPad-based survey. This descriptive study examined trends in mobile phone ownership and feasibility of and interest in mHealth across sociodemographic categories. Fisher's exact tests were used to evaluate associations. Univariate logistic regression models were fitted to calculate odds ratios and 95% confidence intervals. Results. Of 220 participants, 82.3% and 95.0% reported mobile phone ownership and access, respectively. Ownership was significantly associated with educational level (P = 0.031); however, even among mothers with the lowest education, ownership approached 80%. Educational level and age, respectively, were associated with the ability to open (P < 0.001; P < 0.001), read (P < 0.001; P < 0.001), write (P < 0.001; P < 0.001), and send (P = 0.006; P = 0.047) text messages. Over 85% of mothers were interested in using their mobile phones to receive health advice for their child and to seek help during illness. Regression analyses revealed that ability to use a mobile phone was positively associated with the mother's intention to participate in the mHealth program. Conclusions. The study findings confirm widespread access to mobile phones and sufficient ability to utilize text messaging within this population of caregivers. In addition to access and feasibility, high levels of interest in using mobile phones for health-related purposes suggest the potential value associated with an mHealth program designed to improve childhood illness management in this community.