The more than $4 million project builds on the pilot scheme at two Dunedin Hospital wards, which resulted in common medication errors such as illegible drug names and patient identification issues eliminated.
Southern DHB medical director of IT Dr Andrew Bowers said electronic prescribing would be introduced in Southland, Dunedin and Wakari hospitals.
Community trust-run hospitals and Lakes District Hospital were not included at this stage, with the exception of Clutha Health First in Balclutha.
In addition, Southern was the lead DHB helping other South Island DHBs implement electronic prescribing, with Christchurch Hospital first on the list.
Canterbury's plans were also advanced but required final funding approval.
"We are developing a regional medication safety group, which represents a level of collaboration between DHBs that we have not seen before."
The Ministry of Health has directed DHBs to have electronic prescribing in hospitals by the end of 2014.
Southern is an information technology leader, having been the site of the 2010 trial, and an earlier 2004 pilot in Dunedin, which was an Australasian first.
While the national target was "ambitious", Southern was well placed to implement electronic prescribing by mid-2014 "at the latest".
Electronic prescribing should prevent 70-80 medication error deaths throughout New Zealand, Dr Bowers said.
New Zealand Institute of Economic Research had calculated the money spent would be more than recouped through fewer medical errors and better patient outcomes.
The 2010 trial at Dunedin Hospital wards 8a and 8b, which has been continued as a pilot scheme, resulted in incorrect or missing information reducing from 82% to nothing.
Dr Bowers, who is also an acute internal medicine specialist at Dunedin Hospital, said international software company CSC would continue providing the software.
Clinicians used a mix of laptops and tablet computers, with a trend towards more use of the latter.
Southern DHB was providing most of the funding, with assistance from the Health Quality and Safety Commission, Dr Bowers said.
