In order to study bio fertilizers and zinc effects on some physiological parameters of triticale under a water-limitation condition, a factorial experiment was conducted based on randomized complete block design with three replications in 2014 and 2015. Experimental factors consisted of three irrigation treatments [normal irrigation (W 0 ); moderate water limitation (W 1 ) and severe water limitation (W 2 )]; four bio fertilizers' levels [(no bio fertilizer (F 0 ), application of mycorrhiza (F 1 ), plant-growth-promoting rhizobacteria (PGPR) (F 2 ) and both application PGPR and mycorrhiza (F 3 )] and four nano zinc oxide levels [(without nano zinc oxide (Zn 0 ) as control, application of 0.3 (Zn 1 ), 0.6 (Zn 2 ) and 0.9 (Zn 3 ) g L −1 )]. Results showed that water limitation decreased chlorophyll content, relative water content, stomatal conductance, quantum yield and grain yield of triticale, whereas electrical conductivity and the activity of catalase (CAT, EC 1.11.1.6), peroxidase (POD, EC 1.11.1.7) and polyphenol oxidase (PPO, EC 1.14.18.1) enzymes were increased. Inoculation of plants with bio fertilizers and zinc application improved these traits (except electrical conductivity) under water-limitation condition as well as normal irrigation. Based on the results, it was concluded that bio fertilizers and nano zinc oxide application can be recommended for profitable triticale production under water-limitation condition.ARTICLE HISTORY