According to the preliminary data, operating income in non-financial business economy in the Republic of Serbia in the third quarter of 2018 increased by 5.4% relative to the same period of the previous year, while compared to the second quarter of 2018, the increase of 2.6% was noted. Operating costs in non-financial business economy in the third quarter of 2018 increased by 7% relative to the same period of the previous year, while compared to the second quarter of 2018, the increase of 1.9% was noted.