Decision aids (DA) can inform cancer screening. We conducted a systematic review of web-based, cancer DA to evaluate their appropriateness for use with low literacy and diverse culture groups. Eighty-one Internet DA were found searching five databases (Pubmed-Medline; Web of Science/SSCI; Cancerlit; CINAHL; and Google) and the Cochrane decision aid inventory. Twenty-three met key inclusion criteria of (1) informing cancer screening or treatment decisions, (2) being patient or consumer oriented, and (3) conforming to the Cochrane definition of DA. DA were evaluated using the International Patient Decision Aid Standards checklist, the Cultural Sensitivity Assessment Tool (CSAT), the Cultural Sensitivity Assessment Checklist (CSAC), and the SMOG readability formula. DA had a high readability with 74% (n = 17) written at the grade 10 - 13, 22% (n = 5) at the grade 9, and 4% (n = 1) at the grade 8 level. Visual aids were used in 35% (n = 8) to present probability information. Written information was complemented with video or audio components in 35% (n = 8). Most (91%, n = 21) were developed for generic audiences, while 9% (n = 2) specified a cultural group. Although DA enabled a step-by-step movement through the website, none allowed key word searches and only 65% permitted document printing. Most DA included difficult texts and were not focused for specific cultural groups.