The objective of this study was to characterize the relationship between lying behavior and subclinical ketosis (SCK) in transition dairy cows. A total of 339 dairy cows (107 primiparous and 232 multiparous) on 4 commercial dairy farms, in Eastern Ontario, Canada, were monitored for lying behavior and SCK from 14 d before calving until 28 d after calving. Daily lying time was measured using automated data-loggers 24 h/d. A blood sample was taken from the coccygeal vein of each cow for measurement of β-hydroxybutarate (BHBA) 1x/wk. Cows with BHBA ≥1.2mmol/L postpartum were considered SCK. Cases of retained placenta, metritis, milk fever, or mastitis during the study period were also recorded. Cows were categorized into 1 of 3 groups: healthy (H) cows had no SCK or any other health issue (n = 139); SCK (K) cows with no other health problems during transition (n = 97); or ketotic plus (K+) cows that had SCK and one or more other health problems (n = 53). Data were summarized by wk and analyzed in a repeated measures general linear mixed model. A 3-way interaction was found between parity, disease status, and wk (P < 0.001); thus, first lactation and multiparous (MP) cows were analyzed separately. There was no difference among H, K and K+ (P = 0.5) in daily lying time from 2 wk before (−2) to 4 wk after calving (+4) for first-lactation cows. In MP cows, an interaction of disease status and week was detected (P < 0.001). Prior to calving, lying time was similar for MP cows (746 ± 32.8 min/d), decreasing (P < 0.001) after calving to an average of 598 ± 10.8 min/d. Differences in lying time for MP cows were seen in wk +1 when K+ cows spent 92 ± 24.0 min/d more time (P < 0.001) lying down than H cows, and during wk +2 where K+ cows tended (P = 0.07) to spend 38 ± 21.3 min/d more time lying down than H cows. Differences in lying time were also seen in MP cows in wk +3 and +4 where K cows spent 44 ± 16.7 min/d and 41 ± 18.9 min/d, respectively, more time (P ≤ 0.03) lying down than H cows. Overall, these results suggest that monitoring lying time might contribute to identifying MP cows experiencing multiple health issues, including SCK, after calving.