The concentration of total lipids and cholesterol in the plasma of 72 clinically healthy hens of 3 laying lines (BPR, RIR and SU) was studied during the laying period (days 121, 149, 189, 240, 310 and 358 of age). The average total lipid concentration in all lines was the lowest prior to and at the beginning of egg production (6.46, 8.19 and 11.39 g/l). The average concentrations of both plasma total lipids and plasma cholesterol were the highest in the peak of the laying period (23.77, 29.42. 32.09 g/l and 3.99, 4.10, 4.12 mmol/l, respectively). Prior to and at the beginning of egg production the correlation between the concentrations of plasma total lipids and cholesterol and the intensity of egg production were positive (r_p = 0.01 to 0.42). With the increasing intensity of egg production and at its peak this correlation was negative for total lipids (r_p = -0.48 to -0.03), for cholesterol in line SU it was negative (r_p = -0.22 to -0.20), in late lines it was positive during peak egg production (r_p = 0.18 to 0.47). The concentrations of total lipids and cholesterol were found to affect both the stage of egg production and the line.