The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is the main vector of Tomato Zonate Spot Virus (TZSV) in Yunnan, China. We investigated the life history parameters of F. occidentalis on tomato and pepper leaves either with or without TZSV infection. The total duration of the immature stages of F. occidentalis reared on TZSV-infected leaves was significantly shorter than the total duration of those reared on uninfected leaves. Also the survival rates of the instars and prepupae on TZSV-infected tomato and pepper leaf disks were significantly higher than those on uninfected tomato and pepper leaf disks. The F. occidentalis populations reared on TZSV-infected tomato and pepper leaf disks respectively increased 11.97- and 10.64-fold in 1 generation, while those reared on uninfected tomato and pepper leaf disks increased only 8.10- and 6.45-fold, respectively. These results demonstrated that TZSV infection improved the fitness and host suitability of its vector, F. occidentalis. Also our findings suggest that TZSV-infection is likely to induce larger field populations of F. occidentalis, thereby increasing the probability of TZSV transmission.