Background Adalimumab is effective for the induction and maintenance of remission in Crohns disease (CD)-patients. Aim To find predictors for adalimumab dose escalation at initiation of adalimumab. Methods Crohn's disease patients in a single tertiary referral centre who started adalimumab between July 2007 and March 2010 at an induction dose (week 0 160 mg subcutaneously (sc), week 2 80 mg sc) and maintenance dose of 40 mg sc thereafter every other week were followed prospectively. Patients on adalimumab for at least 3 months were included. The number of patients needing dose escalation was assessed. Patients that needed dose escalation were compared with patients that did not need dose escalatio Results Of 199 CD patients treated with adalimumab and followed prospectively, 122 patients (M/F 54/68, median age 35 years, range 18-66 years, median CDAI 164, range 6-468) were treated for 3 months. In total 38% of these patients (46 /122) needed a dose escalation within a median time of 21 weeks after adalimumab introduction (range 4-105). Body mass index (BMI) (P < 0.03) and secondary non-response to infliximab (IFX) (P < 0.06) were identified as predictors for dose escalation. Concomitant use of im Conclusions Over one-third adalimumab-treated patients are dose escalated within a median of 5 months. Higher BMI and secondary non-response to IFX treatment are predictive for a dose escalation during adalimumab treatment.