The aim of the current study was to investigate whether continuous consumption of probiotics is advantageous over intermittent consumption. A total of 336 1-d-old Japanese quail chicks were randomly divided into seven experimental groups and administered probiotics throughout the experiment in different manners via, A – no probiotics administered (control group), B – probiotics fed continuously, C – probiotics fed for 2 d on & 2 d off, D – probiotics fed for 1 d on & 4 d off, E – probiotics in drinking water throughout the experiment, F – probiotics in drinking water for 2 d on & 2 d off, G – probiotics in drinking water for 1 d on & 4 d off. Administration of probiotic as feed additive significantly increased body weight gain (P < 0.01). Feed intake was lower (P < 0.01) in group F compared with other groups. The birds in groups C, D and G had the lowest feed conversion ratio (P < 0.01). In comparison with control quails, ileum length and duodenum and ileum villus was higher in probiotic-received birds (P < 0.01). Crypt depth was increased (P < 0.01) by probiotics treatments. Number of goblet cells of duodenum and ileum increased in groups B, C, E and F (P < 0.01). There were no significant differences in heterophil: lymphocyte ratio among the groups. Consumption of probiotics increased the blood serum total immunoglobin (P < 0.01), IgM (P < 0.05) and IgY (P < 0.01) levels. It was concluded that administration of probiotic either in feed or in water improved the quail’s performance and immunity. Regarding advantages of administration of probiotics in drinking water this method is recommended in quail production system