Yeast supplementation of stocker cattle entering the feedlot have shown to increase gain, average daily gain (ADG), dry matter intake (DMI), and feed efficiency (FE) as well as minimize the number of sick days. Supplementing high-risk beef cattle with yeast culture could have implications of increasing performance although the animal is expected to have decreased performance. The purpose of this study was to evaluate the effect of yeast culture supplementation on the gain, ADG, DMI, and FE of weaned, high-risk beef cattle (HRBC) when fed a transition ration. One hundred heifers comingled at Texas A&M for 1 week prior to the start of the study. Heifers were stratified by weight and randomly assigned into 20 pens (N = 20); 5 animals per pen. The control group (CTRL; n = 10) received a grain mixture consisting of ground flax seed, soy hull, dried distiller's grains, corn, cotton seed hull, and a vitamin and mineral premix. The treatment group (YEAST; n = 10) received the same grain mixture except the premix included RYEAST 40 (ICC-USA, INC., Louisville, KY 40202) to be fed at the rate of 9 g/hd/d. Each head received 7 lb/d of concentrate and supplemented with 2% body weight of hay from local sources. Cattle were fed the ration for 42 days with weights recorded every 7 days. Gain, ADG, and FE were compared on a pen basis utilizing the PROC MIXED procedure of SAS (SAS 9.3 SAS Institute Inc; Cary, NC, Ver 9.3). Significance was determined at p ≤ 0.05. Gain, ADG, FE, and DMI between CTRL and YEAST was not significantly different (p > 0.05). The data did not show a benefit of supplementing yeast cultures to increase performance outcomes of HRBC. Further research should be completed in order to investigate if higher dosages of yeast can affect performance.