A new period (P=1d.7175405) of the eclipsing binary system SZ Arietis has been presented. Period changes in different portions of the O-C diagram, with new period, have been estimated. The total change in period (ΔP) ranges from 3.64×10−5 d to 4.24×10−4 d, which is appreciably large. However, leaving the unusual value, the average period change comes out to be of the order of 6×10−5 d. The period changes around the years 1903, 1943, and 1977 are apparent in the O-C diagrams. A sinusoidal variation is also visible in the O-C diagrams which indicates that SZ Ari may be a three-body system, having a period of nearly 66 years.