Appendicitis is a common cause of abdominal pain in children, and is the most common reason for children to undergo emergency abdominal surgery. To guide our research program in this field, we aimed to determine parental understanding with regard to appendicitis and its treatment. We also wished to assess parental preference for non-operative or surgical treatment of children with uncomplicated appendicitis. We asked parents attending a children’s outpatient clinic to complete a brief questionnaire that was interspersed with educational content to rectify any knowledge gaps. A total of 396 parents (of 414 approached) agreed to participate. There were gaps in parental knowledge, including not knowing where the appendix is located (one-third of respondents), not knowing what appendicitis is (40% of respondents), and underestimating the incidence of appendicitis. Parents typically overestimated the risks of complications and dying from both uncomplicated and complicated appendicitis. There was no influence of gender, age, or previous experience of appendicitis on these findings. When presented with the scenario of equal effectiveness of non-operative treatment and surgery for uncomplicated appendicitis, 59% of respondents expressed a preference for non-operative treatment over surgery, while 21% expressed a preference for surgery (20% expressed no preference). These findings are important for clinicians and researchers when discussing appendicitis and treatment options with families, and justify ongoing research into the comparative effectiveness of non-operative treatment and surgery.