Background and Rational: In Lao PDR, relapse of metamphetamine use following discharge from rehabilitation center is unacceptably high (~50%). Good preparedness and IEC provision to the rehabilitated addicts before discharge from the rehabilitation center is likely to be vital to prevent relapse. Effective IEC would probably help to reduce the rate of relapse. Methodology: This was an open cluster-randomized-controlled trial to assess the newly developed IEC package among metamphetamine users. The intervention group received new IEC package (education message + brochure + telephone contact number + follow-up) while the conventional advice was given to control group. The study participants were followed up for 6 months by telephone (at 1, 3, 6 months). The primary endpoint was the relapse rate. Result: One hundred and eighty-one addicts were enrolled in the trial (93 in intervention and 88 in control groups). Ninety-six subjects were male. The overall mean (SD) age of the participants was 26.5 (6.1) years and the overall median (range) duration of drug use was 5 (0.5 – 26) years and these figures were not significantly different between the groups (P=0.50 and P=0.97), respectively). The proportion of the participants who were lost to follow-up was 8%. Sixty percents of the study subjects completed 6-months follow up and this was not statistically different between the groups (P=0.93). The overall percentage of relapse was 39% (65/166) [36% (31/85) in intervention and 42% (34/81) in control groups, P=0.38). The median (range) duration of relapse was 30 (1 – 160) days and this was not significantly different between the groups (P=0.38). In a multiple logistic regression model, contact with drug users following discharge from the rehabilitation center was significantly associated with relapse [AOR = 73, 95%CI = 39 – 405, P<0.001] while having a permanent job following discharge was a protective factor for relapse [AOR = 0.03 (0.004 – 0.27), P=0.002]. Conclusion The relapse rate of metamphetamine use was lower in the group with new IEC package than in control group but this was not statistically significant. Further study with a larger scale is strongly recommended