Neutrophil or platelet to lymphocyte ratio (NLR and PLR) has been proposed to be used as prognostic purposes in a variety of diseases. The aim of this study was to evaluate the usefulness of these ratios in monitoring of response to TNF‐α‐inhibitors in psoriatic patients. Eighty psoriatic patients were included and treated with TNF‐α‐inhibitors for 12 months based on drug protocol. Hematologic indices, including NLR and PLR values were assessed before and after treatment. Data on psoriasis area and severity index (PASI), smoking behavior, alcohol intake habit, nail abnormality, body mass index (BMI), joint involvement, and disease duration were also recorded. PASI scores were improved significantly after one‐year treatment (P = .000). Furthermore, this type of treatment significantly reduced the NLR and PLR (P = .000). These changes were in accordance with PASI scores. Patients with BMI greater than 24.9 had higher, but non‐significant NLR and PLR than normal or lean individuals. Cigarette smokers and alcohol consumers had lower NLR and PLR values than other individuals (P < .05). There was no significant association between NLR and PLR and joint or nail involvement. Although NLR and PLR will not be helpful in primary diagnosis of inflammatory diseases, they could be accounted as monitoring tools in management of psoriasis or globally indicators of inflammation.