Four cyclists have already been killed on NSW roads in the first two months of 2013, worrying the state's authorities.

Transport for NSW says in the whole of 2012, seven cyclists killed on NSW roads.

Centre for road safety general manager Marg Prendergast said the four cyclist deaths to February 20 were "alarming".

Bicycle safety advocacy organisation, the Amy Gillett Foundation, said the spike showed more work needed to be done.

"There has been much good work by road authorities, governments and cycling bodies to improve cycling safety particularly in the area of infrastructure at a time when participation is growing," CEO Tracey Gaudry said.

"Unfortunately these sobering facts say one thing: it is not enough."

The Amy Gillett Foundation was established in memory of the elite Australian cyclist, who was killed while training in Germany in 2005.