Few studies have investigated the behaviour of zoo elephants and how their personality is expressed when exposed to different stimuli e.g. a higher number of visitors. Observing the nocturnal behaviour is especially important, because it reveals information about the welfare of the elephants when they are not normally observed. The nocturnal behaviour of three female African elephants (Loxodonta africana) in Aalborg Zoo, Denmark, was studied to create activity budgets and to evaluate if 1) a period with a 4.8 times increase in visitors affected the nocturnal behaviour; and 2) the three elephants exhibited differences in personality. Behavioural data were collected for six nights between 20:00-06:00, and all-occurrence sampling was used to record all types of behaviour. The average of the three elephants showed that the most common behaviours observed during the night was feeding (43±6%) followed by lying (28±5%) and inactive behaviour (16±5%). The elephants laid down an average of 2.4-3.1 hours per night starting at 20:00, and they never laid down before 22:00. No clear pattern of behavioural changes of the elephants was found when there was an increased number of visitors in the zoo. When comparing the intervals of time, the individuals spent on a certain behaviour, and thereby comparing the individuals, several significant differences were found between the medians and interquartile range (IQR). Significant differences were also found in the slopes of the medians, IQR, skewness, and kurtosis for the distribution of the time intervals of the behaviours between the period with lower number of visitors and the period with a higher number of visitors. In an overall perspective, the results indicated that the elephants displayed distinct personalities.