The Reserve Bank fears the economy is even weaker than when it met one month ago.
Tuesday's board meeting considered new data released since its last meeting showing much lower than expected investment intentions for the third quarter of this year.
After the bank cut rates in February, it published a forecast for economic growth centred on 2.75 per cent for 2015-16.
The investment data casts doubt on that forecast and suggests it will be revised down when the bank updates it in May.
While deciding to keep its cash rate steady in March, the bank issued guidance that "further easing of policy may be appropriate over the period ahead".
The guidance is understood to be the clearest about the future direction of interest rates for about two years.
The governor's statement said "the available information suggests that growth is continuing at a below-trend pace, with domestic demand growth overall quite weak".
The bank is concerned that in the past month investment has slipped more sharply than expected, unemployment has climbed to a 13-year high and that the December quarter economic growth figures (due on Wednesday) are likely to be weak.
Its forecasts already factor in a further rate cut by May. After digesting Tuesday's statement, the futures market factored in a near certain rate cut by May followed by the certainty of another cut by November...
Those two cuts would take the bank's cash rate from 2.25 per cent to 1.75 per cent.
Former Reserve Bank economist Paul Bloxham said Tuesday's meeting was "a nail-biter".
"In the days leading up to the decision, the market had been pricing a 50:50 chance of a cut, so it was a close call," the HSBC economist said.
"The post-meeting statement was fairly short, downbeat, and continued to note that the Australian dollar was overvalued on most measures of fundamental value. Working in the other direction, the statement noted that dwelling prices continue to rise strongly in Sydney."
The only things that could stand in the way of a further cut in interest rates in April or May would be inflated lending to real estate investors or a sharp drop in the dollar.
The bank was "working with other regulators to assess and contain risks that may arise from the housing market".
The Australian Prudential Regulation Authority has warned banks not to lower their standards for investment loans in order to chase business.
A sharp drop in the value of the dollar would boost the economy, making a further cut in interest rates less necessary.
The Australian dollar jumped more than half a cent after the Reserve Bank's decision to leave interest rates on hold. It closed near US78¢.
In The Age and Sydney Morning Herald
. February. Dire forecast led to Reserve Bank cut
. February. The economy is weak. It's why the Reserve Bank cut
. February. Why I expect the Reserve Bank to cut interest rates on Tuesday