Crosses between local cattle and pure Belgian Blue cattle often causes birth difficulty because the calf size is too large. In order to avoid this problem, crossbreeding is not conducted with pure Belgian Blue cattle, but with Belgian Blue crossbreeds. In order to support the crossbreeding program between local cattle and Belgian Blue Crossbreeds, it is necessary to study the semen quality of Belgian Blue crossbreeds. This study was aimed to determine the effect of adding tomato (Solanum lycopersicum) extract to egg yolk citrate diluent on the motility of liquid semen and the viability of spermatozoa in Belgian Blue Crossbreed cattle stored at 5 o C. Semen was collected from a 3-year-old Belgian Blue Crossbreed, using an artificial vagina. Semen examination was carried out at the Animal Physiology and Reproduction Laboratory, Universitas Gadjah Mada. The treatments in this study consisted of egg yolk citrate diluent (Control), egg yolk citrate diluent and 4% of tomato extract (P1), egg yolk citrate diluent and 6% of tomato extract (P2), and egg yolk citrate diluent and 8% of tomato extract (P3). Data obtained from microscopic examination were analyzed using analysis of variance based on Completely Randomized Design (CRD). The results showed that the addition of tomato extract could improve maintaining (P<0.05) motility and viability of spermatozoa stored at 5 o C for 96 hours. Semen motility at P0, P1, P2, and P3 were 36.8%, 42.5%, 41.3% and 46.8%, respectively. The viability of spermatozoa at P0, P1, P2, and P3 was 61.3%, 68.5%, 69.3% and 74.3%, respectively. The addition of 8% of tomato extract presented the best results in maintaining motility (46.8%) and viability of spermatozoa (74.3%) after 96 hours. The conclusion of this study was that the addition of 8% of tomato extract into egg yolk citrate diluent could improve the quality of liquid semen, which included motility and viability of spermatozoa.