Reduction of environmental impacts caused by pollution harmful to metals and alloys is very important. The atmospheric corrosion is a serious problem due to economic and environmental losses. Thus it is important to properly prevent corrosion phenomena. Tannic acid is one of natural, non-toxic, and environment friendly inhibitors of corrosion. The inhibitive action of tannic acid was investigated using linear polarization resistance method. The corrosion parameters: corrosion potential and current as well as polarisation resistance, were determined. Corrosion rate and inhibitive efficiency was calculated for two series of tested samples (metals and alloys). An inhibitive effect of tannic acid concentration and immersion number in tannic acid solution on metal and alloys corrosion was described. Copper appeared to be the most resistant metal to corrosion in the presence of tannic acid. Higher inhibitive efficiency of tannic aid was observed in the case of Inconel 625 alloy than steel due to higher content of Cr and lower content of Fe.