Gastro-intestinal parasitism in pasture raised rabbits was studied during three seasons: winter 2014, summer 2015, spring 2016. For every season, two groups of five movable cages (3 rabbits/ cage) were disposed from weaning to 100d. old, on a sainfoin or on a grass plot. A high prevalence of Trichostrongylus sp. (93% of rabbits) and a 50% increase in the fecal excretion of oocysts was found in spring, particularly in sainfoin pasture (6.5 M. OPG) where the rotation times was shorter. No diarrhoea was observed during the trial; at slaughter (100d old), no intestinal macro-lesions in were found, but 64% of the livers had whitish nodules (E. stiedae). Infection by Trichostrongylus sp. was negatively correlated to the daily weight gain. Fecal excretion of E. flavescens may explain partly the lower daily weight gain (-5 g/d) in spring. Our results suggested to increase the pasture rotation delay over the two months requested by current organic rabbit farming regulation. Introduction: The management of parasitism is one of the major obstacle to the development of organic rabbit farming (Roinsard et al., 2013) which relies on grazing. Rabbits with access to grazing are a priori subject to a greater risk of parasitic infection compared to indoor conventional rabbit farming (wire mesh cages), and in particular with strongyles of stomach (Graphidium strigosum) or small intestines (Trichostrongylus retortaeformis, Trichostrongylus sp.), with possible consequences on the digestive physiology and growth of the host. Coccidiosis (genus Eimeria) is also an important parasitosis in grazing and indoor rabbit breeding systems, but their characterization remains to be determined for outdoor systems. Therefore, our goal was to study gastrointestinal parasitism in grazing rabbits, to improve the knowledge of the parasitic risk of grazing and to consider recommendations for prevention Material and methods: The trial was conducted on the experimental farm of the University of Perpignan, in accordance with the French regulation for organic rabbit farming, during winter 2014/2015, summer 2015 and spring 2016. At each season, 30 rabbits were allotted (according to weaning weight and litter origin) at weaning (between 41 and 48 days of age) in two groups of 15 and housed in movable cages (3 rabbits per cage, figure 1) for 9 weeks, disposed either on sainfoin or a grass plot, with a daily grazing area of 0.4 m² per rabbit. Weekly, a sample of feces was collected for each movable cage. For each sample, counts of nematode eggs (EPG) and of Eimeria oocysts (OPG) by the modified Mc Master method was performed. Every two weeks, Eimeria oocysts were identified at the species level, according to a list of morphological criteria. At slaughter (around 100 days of age), the digestive tract (stomach, small intestine, cecum and colon) of some rabbits (Winter: 10, Summer: 20, Spring: 28) was stored at-20° C until parasitic assessment. The liver was examined for the presence of whitish nodules, characteristic of Eimeria stiedai An analysis of variance for repeated measurements was performed using R software on nematode egg counts after logarithmic transformation (log 10 (x+1)). Total oocystal excretion during the fattening period was analysed by the area under the curve method, calculated for each cage, between the day of age and OPG. A linear regression between the number of Trichostrongylus sp. (after logarithmic transformation) and average daily gain (ADG) with the type of pasture (mostly grass or sainfoin) as fixed effects was performed using the Jamovi software. For significant correlations (P <0.05