The use of waste milk (WM) to feed calves is a common practice in dairy farms to avoid economical losses of milk disposal. The aim of this study was to determine whether there is an increase of antibiotic resistance patterns in E. coli isolated from feces of calves fed either WM or milk replacer (MR). Fecal swabs were collected from 20 ± 5 calves at 6 wk of age from 8 dairy farms. In 4 farms, calves were fed MR and in the other 4 they received WM. Fecal swabs were cultured to obtain 5 E. coli isolates per sample. Each colony was tested for its susceptibility to 9 antibiotics by disk diffusion. Binomial logistic regressions were used to analyze the resistance of E. coli isolates for each calf and for each antimicrobial agent tested. Feeding practice (MR or WM) and the use in the farm of the antibiotic tested (as a disease treatment) were the fixed effects of the model, and farm the random effect. Multidrug resistance profiles among E. coli isolates were described by cluster analyses using the Ward’s minimum variance method. Then, a Chi-squared analysis was performed to assess the distribution of E. coli isolates in each of the 6 clusters defined within the 2 milk-feeding practices. The probability of streptomycin (STR) resistant E. coli isolates was greater (P < 0.05) in calves fed WM than in those fed MR, but the use of STR in the farm did not affect the incidence of E. coli resistance. The number of E. coli resistant to enrofloxacin (ENR) isolated from calves fed WM tended (P = 0.08) to be greater than that from calves fed MR, and the use of ENR in the farm did not affect the incidence of E. coli resistance either. Most colonies isolated (93.9%) were included in 2 of the 6 clusters defined: 1 cluster included resistant E. coli isolates to 1 antibiotic and the other, resistant E. coli isolates to 3 antibiotics. The percentage of E. coli isolates within the most resistance cluster was greater (P < 0.001) for WM treatment than for MR. It is concluded that feeding calves WM increases the presence of antimicrobial resistance in fecal E. coli.