The aim of this study was to determine the effect of four consecutive and non-consecutive days of resistance exercise on leukocyte counts, immunoglobulin G (IgG) and cortisol in resistance trained men. Twelve experienced resistance-trained college-age males (age, 22.5±2.11 years; weight, 72.27±6.59 kg; at least 1 year of resistance exercise (RE) experience) volunteered for this study. All subjects underwent, in a randomized manner, two experimental protocols comprising circuit resistance exercise until exhaustion at 75% of 1RM load, 11 repetitions in each station and 10 stations in each circuit. During four consecutive and non-consecutive day of RE, blood samples were collected at rest in first day (D1), immediately and 3 h after completion of the exercise at fourth day (ID4, 3D4 respectively). The results showed that total leukocytes counts were significantly increased at ID4 and 3D4 compared to D1 in both protocols. Serum IgG levels were significantly increased at ID4 compared to D1 in both protocols. Serum CO levels significantly decreased ID4 and 3D4 in consecutive RE as well as 3D4 in non-consecutive RE. The data indicate that four-day of consecutive and non-consecutive circuit-resistance exercise not only didn’t result in reduction of examined immunological indexes but also induced significant elevation in IgG levels and leukocyte counts as well as reduced cortisol levels. These results suggest a protective role of circuit-resistance exercise against upper-respiratory tract infections. However, further research into the effects of chronic consecutive and non-consecutive circuit RE with different intensities on immunological parameters is needed.