A total of 112 weanling pigs with an average body weight of 6.70 ± 1.31 kg were allotted to one of four experimental diets for a 6 wk feeding trail to evaluate the effects of protected organic acids on growth performance, nutrient digestibility, and fecal microbial counts. Diets consisted of basal diet (CON), CON + 0.2% unprotected organic acid (UOA), CON + 0.1% protected organic acid (POA1), and CON + 0.2% POA (POA2). Feeding POA diets to weanling pigs increased (P < 0.05) the average daily gain (ADG) during 0–2 wk and overall experimental period, and it also increased (P < 0.05) the apparent total tract digestibility (ATTD) of dry matter (DM) compared with UOA. The addition of increasing levels of POA showed greater (linear effect, P < 0.05) ADG, gain/feed ratio, and ATTD of DM. In addition, dietary inclusion of increasing levels of POA linearly increased (P < 0.05) the fecal Lactobacillus counts, whereas the Escherichia coli and Salmonella counts, diarrhea score, fecal ammonia, and acetic acid emissions were reduced (linear effect, P < 0.05). In conclusion, dietary supplementation of 0.2% POA to weanling pigs has the potential to improve growth performance and reduce diarrhea incidence while balancing microbial counts.