To compare changes in low-density lipoprotein cholesterol and other lipids in patients with rheumatoid arthritis (RA) randomised to a 1-year treat-to-target strategy with either adalimumab plus methotrexate or placebo plus methotrexate. Prespecified secondary analyses from the OPERA trial, where 180 early and treatment-naïve RA patients received methotrexate 20 mg once weekly in combination with either placebo or subcutaneous adalimumab 40 mg every other week. Serum lipid levels were measured at baseline and after 1 year. Changes in lipid levels were analysed using mixed linear models based on the intention-to-treat (ITT) population. Overall, 174 patients were included in the ITT population (adalimumab plus methotrexate n = 86; placebo plus methotrexate n = 88). Differences between changes in lipid levels were low-density lipoprotein cholesterol 0.18 mmol/l [95% CI − 0.05 to 0.42], total cholesterol 0.27 mmol/l [− 0.002 to 0.54], high-density lipoprotein cholesterol 0.05 mmol/l [− 0.06 to 0.15], triglycerides 0.11 mmol/l [− 0.08 to 0.29], very-low-density lipoprotein cholesterol 0.03 mmol/l [− 0.05 to 0.12], and non-high-density lipoprotein cholesterol 0.22 mmol/l [− 0.02 to 0.46]. In early RA patients treated to tight control of inflammation over a period of 1 year with either adalimumab plus methotrexate or placebo plus methotrexate, changes in lipid levels were similar. Trial registration number: NCT00660647.