High production of table grapes (Vitis vinifera) in Chile, particularly the cultivar ‘Red Globe’, often necessitates storage beyond 60 days at -0.5°C before the grapes could be sold. This has promoted the development of blue mold (Penicillium expansum), causing watery soft rot and internal breakdown on cold stored grapes. A relative low decay incidence (<2%) has commonly been determined. However, this has considerably limited the commercialization of Chilean table grapes at the international markets. The objectives of this research were: i. To characterize and identified the species ofPencillium associated to table grapes in Chile, ii. To study the population dynamic of Penicillium spp. on table grapes under commercial field conditions, iii. To study the effect of high content of total soluble solids (TSS) on disease development, and iv. To study the ability of Penicillium spp. to grow and to infect table grapes under cold conditions. Thirty two isolates of Penicillium were collected from Copiapó and Nancagua (27º18’ and 34°65’ South lat., respectively) in 2004-2005 growing season. Based on morphological features and growth characteristics P. expansum and P. chrysogenum were identified. Populations of Penicilliumwere low on apparently healthy ‘Thompson Seedless’ berries at the beginning of berry development (5% TSS). However, populations considerably increased at harvest (17% TSS) time. Water activity (aw) below 0.96 reduced mycelial growth of P. expansum and P. chrysogenum. Lesion size was reduced on berries of 23% TSS berries. Four of five P. expansum isolates grew in vitro 0°C having measurable growth after eight days. Similarly, these isolates infected ‘Red Globe’ and ‘Crimson Seedless’ table grapes at 0ºC, developing first symptoms after 30 days of incubation. These results demonstrated that P. expansum can infect and develop symptoms after a long storage at 0ºC. It is possible that table grapes become surface contaminate with conidia of P.expansum before harvest. This is the first report of P. chrysogenum on table grapes in Chile; however, its pathological role remains to be determined.