The purpose of this study was to investigate the effect of apparent porosity on the engineering properties of volcanic rocks. Therefore, 22 volcanic rocks collected from the Eastern Black Sea Region of Turkey were sampled and tested in the current study. Laboratory experiments involved the tests for uniaxial compressive strength (UCS), point load index (Is((50))), P wave velocity (V-p), apparent porosity (n(a) (percent)), and dry unit weight (gamma(dry)) of the rock samples. The same core sample for each rock type was used in these tests, The tested rocks with n(a) < 1 % generally exhibited high fluctuations in the UCS values ranging from 89 to 202 MPa. Hence, the correlation between UCS and Is((50)) was evaluated for both n(a) > 1 % and n(a) < 1 %. Additionally, the n(a) values were correlated with the UCS, Is((50)), UCS/Is((50)), gamma(dry), V-pdry, and V-psat. values in case of the n(a) > 1 % and n(a) < 1 %. The experimental data showed that the apparent porosity values significantly affected the engineering properties (UCS, Is((50)), gamma(dry), and V-p) of the rock samples tested. Generally. a satisfactory correlation among the engineering properties of the rocks was obtained only for n(a) > 1 %. Only a weak correlation (R-2 = 0.4) was present between the V-pdry and n(a) for the rock samples having n(a) < 1 %.