OBJECTIVES: To focus on the Bulgarian market of M01 group for the period 1999-2001; the most consumptive active principles (APs) within M01; to determine the trend in M01 consumption and within. METHODS: M01 consumption at national level has been calculated by ATC/DDD methodology and expressed in DDD/1000/day. Data have been collected from: a) the import of wholesalers, b) the local industry sale reports for the domestic market. Comparison has been made with M01 consumption in Norway and Sweden (expressed in DDD/1000/day). RESULTS: M01 consumption at national level has been calculated as follows: 1999 - 14,216; 2000 - 13,764; and 2001 - 15,565. The most consumptive APs within M01 were: Diclofenac (D) 1999 - 8,448; 2000 - 8,728; and 2001 - 9,753; Piroxicam (P) 1999 - 3,380; 2000 - 2,892; and 2001 - 2,761; Indometacin (Ind) 1999 - 1,457; 2000 - 1,061; and 2001 - 1,104; Ketoprofen (K) 1999 - 0,192; 2000 - 0,439; and 2001 - 0,699; Tenoxicam (T) 1999 - 0,598; 2000 - 0,172; and 2001 - 0,699. Ibuprofen (Ib) consumption was: 1999 - 0,169; 2000 - 0,030; and 2001 - 0. The coxib Rofecoxib (R) consumption was registered initially in 2001 - 0,054. CONCLUSIONS: M01 consumption 1999-2001 did not show significant variations. The national demand for M01 is approximately 14 DDD/1000/day. M01 consumption in Norway and Sweden was higher. D as the most consumptive AP at a national level was about 67% of M01 consumption due to 4 locally produced products. Dynamics within the group was: D and K increased slightly; Ind showed relatively steady-state position; P slightly decreased; the trend in T consumption could not be defined distinctly; Ib decreased in consumption; Coxibs were with limited place within M01. In comparison with Bulgaria, M01 consumption model in Norway and Sweden showed some differences.