The survey, conducted from August 2-7 accross the country, found that 42.4 percent of respondents disapprove of President Humala's job performance.
Humala's approval rating increased by 2.6 percentage points compared to a similar poll conducted in June, while his disapproval dropped by 1.1% from that month.
According to the poll, 17% of respondents welcomed the launch of government-run social programs such as Pension 65, Juntos, Cuna Mas, Beca 18 and Samu; while 7.9 percent were happy with the country's economic stability.
In addition, the poll showed that 31.6% of respondents supported President Humala's move to provide cancer patients with free care services, especially for those living in poverty.
A total of 1,450 people were surveyed for the poll which has a margin of error of plus or minus 2.6 percentage points.