In 2001, Lincoln University and six commercial, education and research partners established a 161 hectare dairy farm (milking platform) and formed the South Island Dairy Development Centre (SIDDC) to demonstrate ‘best practice’ for South Island dairy farmers. In 2008, to assess the impact of the Lincoln University Dairy Farm (LUDF), a survey was sent to 622 farmers located in the LUDF extension catchment. Responses totalled 146 (24% response rate). The mean age of respondents was 45 years with 77% having some form of tertiary education. Respondents had higher milksolids production per cow (419 kg) and per hectare (1441 kg) than the Canterbury averages (381kg and 1224kg respectively). Most respondents (86%) identified themselves as using moderate levels of supplementary feeding (Systems 2, 3, 4). Nearly 70% of respondents attended at least one focus day (field day) over a three year period. Most attended to learn about grazing and animal management, to benchmark against the LUDF from a production and financial standpoint, and to learn about environmental management. Focus day attendees had larger operations and higher levels of productivity than those who never attended. Over 68% of respondents visited the farm website each year, with some visiting more than 30 times, but mainly to view benchmarking data rather than to learn about new technologies Of the technologies promoted by the LUDF, 82% of farmers had adopted low grazing residuals and 74% had re-grassed paddocks based on monitoring. Lower numbers had adopted synchronisation of heifers to calve a week before the main herd (29%), aggressive hormone intervention for non-cycling (42%) and a nil induction policy (36%). Over 70% felt that the adoption of some of the LUDF technologies had made their farm management easier. Twenty three farmers were willing to place an economic value on the adoption of LUDF practices. These ranged from NZ$50,000 per year to NZ$1,000,000 per year. It is concluded that a demonstration farm with clearly defined extension messages can be effective at achieving farmer adoption that adoption is high for messages where farmers see clear economic advantages, and that farmers obtain information from a wide variety of sources.