Efficacy and safety of protein kinase C inhibitor sotrastaurin (STN) with tacrolimus (TAC) was assessed in a 24‐month, multicenter, phase II study in de novo liver transplant recipients. A total of 204 patients were randomized (1:1:1:1) to STN 200 mg b.i.d. + standard‐exposure TAC (n = 50) or reduced‐exposure TAC (n = 52), STN 300 mg b.i.d. + reduced‐exposure TAC (n = 50), or mycophenolate mofetil (MMF) 1 g b.i.d. + standard‐exposure TAC (control, n = 52); all with steroids. Owing to premature study termination, treatment comparisons were only conducted for Month 6. At Month 6, composite efficacy failure rates (treated biopsy‐proven acute rejection episodes of Banff grade ≥1, graft loss, or death) were 25.0%, 16.5%, 20.9% and 15.9% for STN 200 mg + standard TAC, STN 200 mg + reduced TAC, STN 300 mg + reduced TAC and control groups, respectively. Median estimated glomerular filtration rates were 84.0, 83.3, 81.1 and 75.3 mL/min/1.73 m2, respectively. Gastrointestinal events (constipation, diarrhea, and nausea), infection, and tachycardia were more frequent in STN groups. More patients in STN groups experienced serious adverse events compared with the control group (62.3–70.8% vs. 51.9%). STN‐based regimens were associated with a higher efficacy failure rate and higher incidence of adverse events with no significant difference in renal function between the groups. This phase II randomized study demonstrates that sotrastaurin in combination with tacrolimus shows higher efficacy failure and higher incidence of adverse events with no significant improvement in renal function compared to mycophenolate mofetil and standard‐exposure tacrolimus in de novo liver transplant recipients. See editorial by Trotter and Levy on page 1137.