Abstract'Mates in Construction' (MATES) is a large-scale multi-component suicide prevention program for construction workers, initiated in Queensland in February 2008, and now disseminated to three additional Australian states. MATES uses on-site universal psychoeducation to encourage help-seeking and early intervention through 'Connectors' trained in suicide first aid and supported by outreach, case management, a 24-hour telephone response line, and online counseling. This review of the first five years in Queensland demonstrates broad program acceptability by workers, unions and construction companies. However, funding constraints and the size and geography of the State limited the overall reach to 35,761 workers from 476 building sites completing the first step in the program -General Awareness Training. Despite this, we compared suicide rates in Queensland male construction workers for the five years of the program (2008)(2009)(2010)(2011)(2012) with the five years prior (2003)(2004)(2005)(2006)(2007), in the context of general male suicide rates for Queensland and Australia for the two time periods.Against a relatively stable male suicide rate for Australia as a whole, the overall male suicide rate (ages 15-64) for Queensland rose during the five years 2008-2012. In contrast, the age-adjusted male suicide rate in the Queensland Construction Industry decreased 7.9% for the years 2008-2012 compared with 2003-2007. Despite small numbers, we attempted statistical analysis using Negative Binomial Regression. The apparent reduction was not statistically significant (95% CI [-0.4, 15.6]), (p=0.386 NS). The decrease for lesser skilled workers (machine operators/ labourers) was 22.5% (95% CI [-6.9, 43.8]), (p=0.121), relative risk 0.80 [CI 0.60, 1.08], again not statistically significant. For skilled trades, the relative risk was 1.04 [CI 0.81, 1.34, NS], a point increase in chance of suicide of 4.1% 33.7, NS]. The complexity of the program and our results are discussed.