Two experiments (Exp) were conducted to evaluate the effects of inclusion of probiotic (P) or organic acid (O) and Catfish (Pangasius hypophthalmus) by-product meal (CBM) in diets on performances of weaned and growing-finishing pigs. Exp1: Forty-five crossbred castrated (Yorkshire x Landrace) male piglets at weaning were allocated into five treatments, 3 replications (pen) with 3 piglets/pen in a randomized completed block design. The control diet was commercial feed (CF), which use fish meal as main protein source, and the experimental diets consisted of four different diets, in which main protein source from CBM without (CM) or with probiotic (CMP), organic acid (CMO) or with both (CMPO) supplementation at 0.2% in the diets. Exp2: Treatments were similar with that in Exp1, thirty male growing pigs (25.0±1.8 kg) were allocated into 5 treatments and 6 replications in 30 individual pens. The results in both experiments showed that, average daily gain (ADG) was the lowest in pigs fed CM and the highest was in pigs fed CF. Feed consumption (ADFI) were non-significant difference between treatments. As results, feed conversion ratio (FCR) was the highest in CM and the lowest in the CF, the probiotic supplementation was better results than the other feed additive supplementation in both growing and finishing phases. Piglets fed organic acid and commercial feed diets were less affected by diarrhoea as comparable with piglets fed other diets. Carcass yield was not affected by treatments. However, back fat thickness increased with CM diet compared with that from CF. Ether extract contents of Longissimus dorsi muscles increased with CM diet. There is no diference of meat color value from pigs fed all diets. In conclusion, it is better to combine the CBM and probiotic or organic acid or both in diets for weaned piglets and growing-finishing pigs, resulting in improving ADG, FCR and reduced diarrhoea incidence and faecal score in weaned piglets as comparable with commercial feed. Key words: Probiotic, Catfish by-product meal, organic acid, weaned piglets, growing-finishing pigs.