OBJECTIVE: To evaluate the effects of an information film on making an informed choice regarding Down syndrome screening, and women's knowledge and experiences of information. METHODS: Randomized controlled trial including 184 women in the intervention group and 206 controls recruited from maternity units in Stockholm, Sweden. The intervention was an information film presented as a complement to written and verbal information. Data were collected via a questionnaire in gestational week 27. Three different measures were combined to measure informed choice: attitudes towards Down syndrome screening, knowledge about Down syndrome and Down syndrome screening, and uptake of CUB (combined ultrasound and biochemical screening). RESULTS: In the intervention group 71.5% made an informed choice versus 62.4% in the control group. Women in the intervention group had significantly increased knowledge, and to a greater extent than the control group, experienced the information as being sufficient, comprehensible, and correct. CONCLUSIONS: An information film tended to increase the number of women who made an informed choice about Down syndrome screening. Participants were more satisfied with the information received. PRACTICE IMPLICATIONS: Access to correct, nondirective, and sufficient information is essential when making a choice about prenatal diagnostics. It is essential with equivalent information to all women.