Two experiments were conducted to determine the effects of Biolex™ feed additive (BioMatrix International, Princeton, MN) on growth performance of wean-to-finish (Experiment 1) and nursery (Experiment 2) pigs. Experiment 1 utilized 352 crossbred pigs (5.78 kg BW) allotted to pens (11 pigs/pen; 16 reps/trt) on d 0 and fed a common diet for 28 d. On d 28, pens were assigned randomly to 1 of 2 dietary treatments. The two dietary treatments consisted of a fortified corn-soybean meal-DDGS based diet serving as the control and the control diet + Biolex™ (0.10%). Pigs were fed in 5 dietary nursery and 6 finishing phases. Feed disappearance and BW were recorded to calculate ADG, ADFI, and G:F. Data were analyzed using the MIXED procedure in SAS with pen serving as the experimental unit. There were no differences (P > 0.10) in final BW (137 vs. 138 kg), ADG (793 vs. 799 g/d), or ADFI (1.96 vs. 1.93 kg); however, pigs fed Biolex™ had improved (P = 0.02) G:F (0.40 vs. 0.41). Biolex™ tended to increase (P = 0.08) loin depth and numerically improve (P = 0.12) percent lean. In Experiment 2, 280 crossbred pigs (5.44 kg BW) were utilized in a 42-d experiment. Pigs were allotted to pens (10 pigs/pen; 14 reps/trt) on d 0 and fed a common diet for 21 d. On d 21, pens were assigned randomly to two dietary treatments. The two dietary treatments consisted of 1) Control and 2) Control + Biolex™ (0.10%). In Experiment 2, there was no difference (P > 0.10) in ADG (367 vs. 372 g/d), ADFI (507 vs. 504 g), or G:F (0.72 vs. 0.74) between diets. These results suggest that Biolex™ fed to nursery and wean-to-finish pigs has no effect on ADG or ADFI but improved G:F in wean-to-finish.