Background The aim of minimising the risks of complications and adverse events is at the centre of surgical practice. This study aimed to formally assess the evidence on which paediatric orthopaedic surgical procedures are described as 'safe'. In particular, the objective was to ascertain the proportion of studies describing a procedure as 'safe', which achieved a 95% upper limit Confidence Interval of risk of 5% or less for major adverse events. Method A primary search of Journal of Paediatric Orthopaedics 2009-2014 for the single term 'safe' returned 71 papers appropriate for analysis. Of these, 60 positively identified an intervention as 'safe'. These papers were read in full and the number of interventions recorded along with the number of complications. Data sets (n = 67) were created and the 95% upper confidence interval calculated for the probability of a complication. Results Only 16 data sets (ex 67) provided evidence that the probability a major complication was under 5%.