The average American adult reads at an 8th-grade level. Discharge instructions written above this level might increase the risk of adverse outcomes for children as they transition from hospital to home. We conducted a cross-sectional study at a large urban academic children's hospital to describe readability levels, understandability scores, and completeness of written instructions given to families at hospital discharge. Two hundred charts for patients discharged from the hospital medicine service were randomly selected for review. Written discharge instructions were extracted and scored for readability (Fry Readability Scale [FRS]), understandability (Patient Education Materials Assessment Tool [PEMAT]), and completeness (5 criteria determined by consensus). Descriptive statistics enumerated the distribution of readability, understandability, and completeness of written discharge instructions. Of the patients included in the study, 51% were publicly insured. Median age was 3.1 years, and median length of stay was 2.0 days. The median readability score corresponded to a 10th-grade reading level (interquartile range, 8-12; range, 1-13). Median PEMAT score was 73% (interquartile range, 64%-82%; range, 45%-100%); 36% of instructions scored below 70%, correlating with suboptimal understandability. The diagnosis was described in only 33% of the instructions. Although explicit warning signs were listed in most instructions, 38% of the instructions did not include information on the person to contact if warning signs developed. Overall, the readability, understandability, and completeness of discharge instructions were subpar. Efforts to improve the content of discharge instructions may promote safe and effective transitions home.