Electronic diaries are increasingly used to assess daily pain in many different forms and populations. This systematic review aims to survey the characteristics of studies using electronic pain diaries and to examine how these characteristics affect compliance. A literature search of 11 electronic databases was conducted. Studies were evaluated on the basis of predetermined inclusion criteria by two independent reviewers. Study characteristics were grouped into four categories: general, population, electronic diary, and sampling procedure (i.e., response, attrition, and compliance rates) including strategies to enhance compliance. The 62 included publications reported from 43 different datasets. Papers were usually written in English and published as from 2000. Samples mostly consisted of female chronic pain patients aged 19-65 years from western countries. Most diaries held less than 20 items and were completed up to 6 times daily at fixed or prompted times for 1 month at most. Less than 25% of the studies reported both response and attrition rates; however, a majority reported compliance. Compliance was generally high, and positively associated with shorter diaries, age, having a user's manual, financial compensation and using an alarm. It is important that the various study characteristics are catalogued carefully, especially response and attrition rates, because they can affect compliance. Measures of momentary pain are often developed for the purpose of a certain study; standardisation and validation of these measures is recommended. Finally, authors should mention whether they report on data that has also been used in previous studies.