The aim of this study was to determine if fescue toxicosis altered blood perfusion in the corpus luteum (CL), and peripheral concentrations of progesterone (P4) in cattle. In 2 replicates, the estrous cycles of 36, non-pregnant Angus or Charolais cows were synchronized using the CO-Synch+CIDR protocol. Seven d after initiation of the protocol, cows were assigned (d 0) to 1 of 2 treatments: 2.5 kg of (1) Kentucky-31 endophyte-infected (E+; n = 14), or (2) MaxQ novel endophyte (NE; n = 12) tall fescue seed. On d 7 ovaries were examined using ultrasonography and only cows that had 1 CL present remained on the study (n = 26). Images of blood perfusion of CL, blood samples, rectal temperatures, and blood pressure of tails were collected on d 10, 13, 15 and 18. Images of CL blood perfusion were analyzed using ImageJ software for pixel density, and scored visually (0 to 9 with 0 = no perfusion, 9 = complete perfusion) by 2 independent technicians. The MIXED procedure of SAS was used with day as a repeated measure. LSMeans and pooled SEM are reported. Cows receiving E+ had greater rectal temperatures (P = 0.02; 38.73 ± 0.08°C) than those receiving NE (38.46 ± 0.08°C), providing evidence the cows treated with E+ were influenced by fescue toxicosis. Pulse pressure and mean arterial pressure were decreased (P < 0.01) in cows receiving E+ (54.08 ± 3.21 and 80.06 ± 2.71 mmHg, respectively) than NE (67.12 ± 3.11 and 91.37 ± 2.93 mmHg, respectively). Concentrations of P4 were similar (P = 0.54) between cows receiving E+ (6.04 ± 0.53 ng/mL) or NE (6.36 ± 0.63 ng/mL). Pixel densities (P = 0.14) and visual perfusion scores were similar (P = 0.11) between cows receiving E+ (1,477.20 ± 655.62 pixels and 2.23 ± 0.34, respectively) or NE (2,934.70 ± 718.20 pixels and 3.00 ± 0.36, respectively). Mean CL volume was similar (P = 0.39) between treatments. In conclusion, blood perfusion of CL or peripheral concentrations of P4 were not altered at the onset of fescue toxicosis, indicating that a decrease in blood perfusion of the CL may not be a primary mechanism involved in decreased reproductive efficiency of cattle during fescue toxicosis.