A factorial experiment (4×3) was conducted to evaluate the productive performance of laying hens fed diets containing four plant protein sources [soybean meal (SBM), sunflower meal (SFM), rocket seed meal (RSM) and their combination] either without or supplemented with probiotics (Nutri-Bio Plus, 0.5 g/kg) or enzyme preparation (Natuzyme, 0.5g/kg). One hundred and eighty, 20-week-old Hy-Line W-36 hens were randomly assigned to 12 equal experimental groups, each with five replications. All birds were kept in community battery cages (3 birds per cage), set up in an open-sided laying house, and exposed to a daily photoperiod of 16 hr and managed similarly. Twelve pellets experimental diets were formulated to contain metabolizable energy of about 2800 kcal/kg and crude protein of about 17%. Feed and water were provided ad libitum throughout the experimental period (20-44 weeks of age). The performance criteria included body weight, productivity (daily feed intake, egg production, egg weight, daily egg mass, feed conversion and economic efficiency), some egg quality traits, nutrients digestibility and certain blood parameters (total lipids, total protein, albumin, globulin, total calcium and inorganic P and activity of alanine aminotransferase and aspartate aminotransferase). The most important results can be summarized as follows: Apart from the effect of feed additive, feeding the SFM- and combined plant proteins produced positive effects on egg production rate, feed conversion, and economic efficiency from 20 to 44 weeks of age. Hens fed the SFM, RSM and combined plant protein-diets consumed significantly less feed but exhibited superior means of body weight gain, yolk index, yolk color score and shell thickness as compared to their control counterparts; other criteria were not affected. Also, significantly higher means of digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), crude fiber (CF) and nitrogen-free extract (NFE) were observed for cockerels in response to feeding the SFM, RSM and combined plant protein-diets compared with those of the control group. Although hens fed the probiotics and enzyme-supplemented diets consumed significantly less feed, they achieved superior means of body weight gain, egg production rate, egg weight, feed conversion, economic efficiency, shell thickness, shell weight per unit surface area, yolk color score and Haught units as compared to the control group, regardless of the effect of dietary protein source, however; other parameters were not affected. Moreover, cockerels fed the probiotics and enzyme-supplemented diets achieved superior means of digestibility of DM, OM, CP, EE, CF and NFE as compared to their control counterparts. There were significant interactions between dietary protein source and feed additive only for body weight gain, shell thickness and shell weight per unit surface area, but not on other criteria of response. Based on these results, it could be concluded that sunflower meal and rocket seed meal can be used as safe feed ingredients in laying hens diets (at levels of 14-15% or their mixture at a weight ratio of 1:1), with or without enzyme or probiotics addition. Taking the economic aspect into account, the priority of choosing plant protein sources could be directed into SFM plus RSM, followed by SFM and then by RSM, in descending order.