The objective of this study was to test the efficacy of specially designed educational materials to correct misperceptions held by smokers about nicotine, nicotine medications, low tar cigarettes, filters and product ingredients. To accomplish this, 682 New York State Smokers' Quitline callers were randomized to one of two groups: control group received counseling, nicotine patches and quit smoking guide; and experimental group received counseling, nicotine patches, quit guide, plus information about cigarette characteristics mailed in a brand-tailored box. Participants were contacted 1 month later to assess knowledge about cigarettes and actions taken to alter smoking behavior. The results found that respondents in the experimental condition were more likely to report using and sharing the test materials with others compared with the control condition. Overall mean knowledge scores for the experimental group were slightly higher compared with those who received the standard materials. Knowledge of cigarette ingredients was not related to quit attempts or quitting smoking. This study found that the experimental materials were better recalled and contributed to higher levels of knowledge about specific cigarette design features; however, this did not translate into changes in smoking behavior. (Contains 2 tables and 1 figure.)