A survey of infection by Citrus tristeza virus (CTV) was conducted during a visit to 14 citrus orchards in different regions in Tartous governorate in the Syrian Coast during the spring of 2012. We collected a total of /691/ samples of different varieties. Most of the samples were collected from plants with symptoms similar to symptoms caused by viral diseases (dwarfing, yellowing, mosaic, quick- decline, vein clearing, boat or spoon-shaped leaves), while other samples did not carry such symptoms due to the possible presence of latent infections. The samples were tested by using Tissue Blot immunoassay (TBIA). The Results showed that the rate of infection by CTV was 34.15% in the tested samples and the distribution of CTV in citrus orchards was by various ratios. The highest percentage of infection was detected in AL- Hamidiah (62.50%), whereas the lowest infection percentage detected was in Talin nursery (10%). Common orange Balady was the most infected by Citrus tristeza virus (41.43%). No virus infection was recorded in Mandalina samples.