Objectives: Peripheral intravenous (IV) access is a standard procedure in clinical settings. Nevertheless, previous studies have indicated that difficult peripheral IV access is prevalent in children. This study aimed to determine the prevalence and factors contributing to difficult peripheral IV cannulation in children admitted to a tertiary care hospital in Oman. Methods: This cross-sectional study was conducted from September to December 2015 at Sultan Qaboos University Hospital in Muscat, Oman. Nurses collected data concerning factors contributing to difficult IV access in children. Results: A total of 511 children undergoing cannulation during the study period were included in the analysis. Overall, 23.3% of the children experienced two or more cannulation attempts. The study identified three variables associated with successful cannulation in cases of difficult IV access. Visible veins were 2.72-times (95% CI: 1.58–4.68) more likely to be associated with success (p < 0.001), while palpable veins were 2.22-times (95% CI: 1.29–3.83) more likely to be associated with success (p = 0.004). However, scarring from previous IV access attempts was half (95% CI: 0.31–0.77) as likely to be associated with successful cannulation (p = 0.002). Conclusions: We identified statistically significant variables related to difficult IV cannulation in children, which we used to develop a prediction tool to assess the likelihood of difficult IV access in pediatric patients. Further research is necessary to validate the use of the difficult IV access prediction tool in this population.