As activity levels of intensively managed broiler chicken vary over time, detailed knowledge on their influence is potentially useful to further adjust welfare assessment schemes. Therefore, this study investigated the influence of daytime and age on the performance of broiler chicken in applied fear tests. On-farm studies were carried out in eight flocks of intensively managed Ross-308 broiler chicken of three Danish producer. A forced and a voluntary approach test were conducted during morning and evening hours and at three different ages (1: 6-12d; 2: 21-24d; 3: prior to slaughter). At each observation, avoidance distances (AD) and the number of animals voluntarily approaching (VA) an observer were collected. Spearman correlation was used to investigate the effect of daytime on avoidance and approach, Mann-Whitney-test was used to look for differences in the distribution of the individual data sets. No significant correlation was found between daytime and AD or VA. When comparing data from morning and evening collected at different ages, significant difference could be found in the distribution of the VA at all ages (1: r= 0.56*; 2: r= 0.40*; 3: r= 0.64*) but not for the AD. However, at three weeks the VA was found to be higher in the morning but at younger age and prior to slaughter, more birds approach an observer in the evening. Both, approach and avoidance peaked at three weeks with the latter decreasing to a minimum prior to slaughter. As activity and behaviour are known to vary over the day, detailed knowledge on their influence is potentially useful to further adjust welfare assessment schemes. From the results of this study I conclude, that the time of assessment has no effect on avoidance or approach behaviour of commercial broiler chicken. This makes the applied tests potentially applicable independent of time restrictions.