OBJECTIVES:  In cost-utility analysis (CUA) of medical and public health interventions, results are usually expressed as incremental cost-effectiveness ratios (ICERs) using quality-adjusted life years (QALYs) as health outcome measure. To calculate QALYs, a utility weight representing the health-related quality of life needs to be assigned to each of the health states under consideration. The objective of this systematic review was to give a comprehensive overview of studies estimating utility weights for influenza and influenza-like illness (ILI). METHODS:  A literature search was performed using the PubMed database. Search results were limited to articles published from 1990/01/01 to 2016/02/29 in English, German, French, Italian, Portuguese, or Spanish. The database search was supplemented by manually scanning the reference lists of retrieved full-text articles and searching Google. A study was included if it estimated utility weights for influenza or ILI based on primary data (including author/expert-based assessments). RESULTS:  Fifteen studies were included in the review. They were conducted in the USA, Canada, Australia, and various European countries. Eleven studies used preference-based instruments (e.g. EQ-5D, HUI3, or QWB). The remaining four studies were based on rating scale scores, with three studies converting these into time-trade off (TTO) equivalent scores. Reported utility values ranged from ‑0.342 to 0.90 and differed by the timing of assessment during the influenza episode and the type of health care provided (outpatient cases vs. hospitalised cases). Four studies reported estimates of quality-adjusted life day (QALD) losses ranging from 1.6 to 11.3 per episode. CONCLUSIONS:  This systematic review revealed that utility weights for influenza and ILI varied widely across published studies. Since methods used to estimate utility weights also differed considerably, researchers should attach great importance to the careful selection of utility weights when conducting CUA.