Paediatric electroencephalograms (EEG) can be difficult to perform due to poor compliance from the children. At times, this can become extremely distressing for both the child and their carer. This can result in staff spending excessive periods of time attempting to obtain a reasonable recording, thus reducing the overall efficiency of the department. This study aimed to assess the effectiveness of melatonin sleep investigation in the diagnosis of paediatric epilepsies in Clinical Neurophysiology, Ninewells Hospital (Dundee). Melatonin is used in clinical neurophysiology to obtain a sleep electroencephalogram (EEG) to detect inter-ictal epileptiform discharges (IEDs) and contribute to the diagnosis of epilepsy. 44 individuals who were referred for both a routine and melatonin sleep EEG were assessed in this study. Each recording was retrospectively assessed by the investigator and the number of IEDs, the amplitude of the alpha activity and the tolerability of the patient were measured. When the number of IEDs in the routine were compared to the first 20 minutes of the melatonin sleep investigation the percentage increase was 94.3%. A similar result was found when the amount of IEDs in the remainder of the melatonin sleep was compared to the routine recording (92.9%). A Wilcoxon signed-rank test proved that this change was statistically significant (p=0.0010; p=0.0020). Using a Mann-Whitney statistical test it was shown that melatonin did not appear to have any significant effects on the tolerability of the EEG (p>0.9999). The assessment concerning the change in the alpha amplitude was conflicting; two separate statistical tests (Wilcoxon signed-rank test; Kolmogorov-Smirnov test) demonstrated different p-values (0.0421, 0.8079). In total, 27.27% of the participants were given a diagnosis suggestive of epilepsy. The study showed that melatonin sleep investigations significantly increased the number of IEDs compared to routine EEGs; while having no significant effect on tolerability or the baseline EEG.