This article presents the results obtained by determining the activity concentration of radionuclides and the index of radioactivity for different cements.

Determinations were made for cements without additions and with additions of limestone, slag and limestone, fly ash, puzzolana and limestone, slag, slag and puzzolana.

The data obtained, indicate dependency of concentrations of radionuclides and the radioactivity index of the types and percentages of additions. The conclusions reveal that, when determining the types and percentages of the additions in cements, it also must be taken into consideration classification of the radioactivity index within the limits permitted in Romania.