Objective of the study was to evaluate factors affecting pregnancy per embryo transfer (PET) in dairy cattle. A total of 10,634 transfers in 6,734 Holstein dairy cows (primiparous = 2,287; multiparous = 1,907) and heifers (n = 6,440) from a 4,500-cow commercial herd in Northern Florida, were used. Data on collection year (2011–2014), transfer season (fall, winter, spring, summer), semen type [conventional (C), sexed (S)], embryo type (Fresh, Frozen, IVF, IVF-Frozen), embryo developmental stage (4 - morula, 5 - early blastocyst, 6 - blastocyst, 7 - expanded blastocyst, 8 - hatched blastocyst), embryo quality grade (1 - excellent/good, 2 - fair, 3 - poor), recipient parity (N - nulliparous, P - primiparous, M - multiparous), recipient estrous cycle day (5, 6, 7, 8, 9), technician (1, 2, 3, 4), DIM, and milk yield at the time of transfer were collected. The embryos were produced in vivo (superstimulation and uterine flush 7 d after AI) or in vitro (ovum pick-up, fertilization, in vitro culture for 7 d). Pregnancy was diagnosed at 41 ± 3 d of gestation. Data were evaluated by mixed logistic regression using the GLIMMIX procedure of SAS using all data listed as fixed effects and recipient ID as random. PET was affected by embryo type (Fresh = 48.1%, Frozen = 36.6%, IVF = 38.9%, IVF-Frozen = 32.6%; P < 0.001), embryo stage (4 = 36.4%, 5 = 34.1%, 6 = 38.2%, 7 = 45.2%, 8 = 37.1%; P < 0.001), embryo quality (1 = 42.1%, 2 = 32.6%, 3 = 23.5%; P < 0.001), recipient parity (n = 41.9%, P = 37.7%, M = 31.6%; P < 0.001), recipient estrous cycle day (5 = 32.6%, 6 = 36.4%, 7 = 40.8%, 8 = 40.4%, 9 = 36.6%; P < 0.001), technician (1 = 33.9%, 2 = 33.5%, 3 = 38.0%, 4 = 43.8%; P < 0.001), semen type (C = 39.9%, S = 37.7%, P = 0.03), transfer year (2011 = 44.2%, 2012 = 41.5%, 2013 = 38.2%, 2014 = 36.5%, P < 0.001). In conclusion, PET was affected by year, semen type, embryo type, embryo stage and quality, recipient parity, recipient estrous cycle day, and technician, but not by transfer season, DIM or milk yield at embryo transfer.