The number of murders across the state has increased by 40 per cent in the two years to March this year, newly released statistics show.

The figures show there were 74 recorded murders last year, up from 53 in the previous year, data from the NSW Bureau of Crime Statistics and Research reveal. Domestic-violence related assaults were up by 6 per cent.

BOCSAR director Don Weatherburn said the almost 40 per cent increase in murders and the spike in domestic assaults needed to be viewed in context.

"It is important not to jump too fast at figures between one year and the next year. The long-term trend is down," Dr Weatherburn said.