The objective of this study was to assess the effect of pre-partum behavioral activity on stillbirth in transition dairy heifers and cows. A behavioral activity index (BAI) was computed for every animal taking into account the number of steps (no./d), standing time (min/d), lying time (min/d), and lying bouts (LB, no./d). A total of 387 Holstein dairy cows (110 primiparous and 277 multiparous) in 3 commercial dairy herds were enrolled at 7 d before calving until 14 d post-calving. Weekly, a cohort of 10 to 15 heifers and cows were enrolled at each farm, and electronic data loggers (IceQube, IceRobotics, Edinburgh, UK) were fitted to the hind leg of individual animals to assess their behavioral activity. Pre-partum heifers and cows were moved into prepartum pens 21 d before the expected calving date. All heifers and cows were housed in similar prepartum free-stall barns and moved into a contiguous individual maternity pen for parturition. Stillbirth was defined as a calf born dead or died within 24 h after birth, and with normal gestation length. The BAI was computed for the last 7 d before parturition to assess differences among primiparous and multiparous cows. Data were analyzed using MIXED procedure of SAS. Primiparous cows (P < 0.05) had greater BAI compared with multiparous cows, and as cows mature (multiparous), they become less active around parturition. Regardless of parity, cows with a stillborn calf had less pre-partum lying time (10.5 h/d; P < 0.05) at calving compared with cows with a calf born alive (12.15 h/d). Primiparous cows with a stillborn calf at calving had a greater prepartum BAI (P < 0.05) with similar lying time before calving compared with primiparous cows with calves born alive. Multiparous cows that had a stillborn calf at calving have reduced lying time (P < 0.05) with similar BAI before calving compared with multiparous cows with calves born alive. These results suggest that monitoring a combination of pre-partum behavioral metrics, such as lying time and BAI, could be used to predict stillborn calves in transition heifers and cows.