To determine the impact of illustrated postoperative instructions on patient-caregiver knowledge and retention. Prospective study with all participants receiving an educational intervention. Pediatric plastic surgical missions in Guatemala City, Guatemala, between 2019 and 2020. A total of 63 majority-indigenous Guatemalan caregivers of patients receiving cleft lip and/or palate surgery. Illustrated culturally appropriate postoperative care instructions were iteratively developed and given to caregivers who were surveyed on illustration-based and text-based information at preoperative, postoperative, and four-week follow-up time points. Postoperative care knowledge of illustration-based versus text-based information as determined by the ability to answer 11 illustration- and 8 text-based all-or-nothing questions, as well as retention of knowledge as determined by the same survey given at four weeks follow-up. Scores for illustration-based and text-based information both significantly increased after caregivers received the postoperative instructions (+13.30 ± 3.78 % SE, + 11.26 ± 4.81 % SE; P < .05). At follow-up, scores were unchanged for illustration-based (-3.42 ± 4.49 % SE, P > .05), but significantly lower for text-based information (-28.46 ± 6.09 % SE, P < .01). Retention of text-based information at follow-up correlated positively with education level and Spanish literacy, but not for illustration-based. In the setting of language and cultural barriers on a surgical mission, understanding of illustration-based and text-based information both increased after verbal explanation of illustrated postoperative instructions. Illustration-based information was more likely to be retained by patient caregivers after four weeks than text-based information, the latter of which correlated with increased education and literacy.