A joint survey for RTL and Stern magazine by Forsa research group found that 52 percent of respondents said they preferred having Merkel as Chancellor.
This is the highest support for Merkel has been since August of last year, when it emerged Germany had suspended EU rules to allow more Syrian refugees to stay, bringing in record numbers of asylum seekers.
Over the past few months, Merkel's approval in the RTL-Stern poll had slipped as low as 44 percent, according to broadcaster NTV.
Merkel's party, the Christian Democratic Union (CDU) and its sister party, the Christian Social Union (CSU) also made a small gain of one percentage point on the previous week, up to now 36 percent.
"Because the Brussels attacks raised the threat of terrorism, citizens are turning around and it's strengthening the established parties - just like after the Paris attacks," head of Forsa research, Manfred Güllner, told Stern.
The slight loss in approval for the young party, founded in 2013, could be attributed to the EU deal with Turkey to take back refugees that leave its shores for Europe, explained Güllner, which has also boosted Merkel's popularity.