Almost 50% respondents said Modi has not done enough to check prices of essential commodities.
The poll conducted by Today's Chanakya, the only pollster that accurately predicted the scale of Modi's election victory in May, showed almost half of the respondents felt the Hindu nationalist leader could have taken more stringent steps to curb inflation.
Modi came to power promising to revive India's flagging economy and reducing prices of essential commodities, but consumer price inflation touched a two-month high of nearly 8 per cent in July while food price inflation neared double digits.
More than two-thirds of those polled said the government's efforts to tackle price rise have remained unchanged or weakened over the last three months, the survey results released in two parts over late Tuesday and Wednesday showed.
Though the Indian economy grew 5.7 per cent in the April-June quarter and recorded its strongest growth in 2-1/2 years, analysts say there is little hard evidence to indicate a sustained rebound.
Ratings agency Moody's on Wednesday said any upgrade to India's sovereign rating is limited by the country's fiscal deficit and inflation outlook.
Still, echoing the sentiment of several other recent opinion polls, a large majority of respondents - 66 per cent - said they were satisfied with the new government's performance so far.
On the issue of corruption, that cost Modi's predecessors dearly in the national elections, 54 per cent surveyed expressed confidence the current government can effectively curb graft that plagues Asia's third-largest economy.
Today's Chanakya, part of a family-run research firm started two decades ago in New Delhi, interviewed 6,280 people across 14 Indian cities between Aug 26 and Aug 31 for the poll.
India among worst ranked nations on tax, inflation
Infrastructure is key to Jan Dhan Yojana's success
India is an 'emerging democratic superpower': Australian PM
Why Moody's won't upgrade India's rating
India ready to defend World Cup, declares Tendulkar