The Palestinian foreign minister has returned from a trip to Muslim nations with $20m in his luggage.
Hamas's financial difficulties have caused widespread hardship
Mahmoud Zahhar crossed the border from Egypt into Gaza with the money in a number of suitcases.
A minister accompanying him said the cash could be used to pay salaries, the Associated Press news agency reports.
The Hamas-led Palestinian Authority has faced a financial crunch since Western donors cut off funding, accusing Hamas of being a terrorist group.
The Islamic militant group refuses to recognise Israel and renounce violence.
The US and EU halted their funding when Hamas took over the Palestinian government after elections in January.
Palestinian hospitals have been struggling to maintain services and families have been selling off their valuables to buy food.
Earlier this month, some Palestinian government workers received some of their salary for the first time in three months.
A senior US envoy has said Washington and the EU are working closely to find ways to give aid to the Palestinian people without dealing with their government.
Several Muslim states have pledged money to the Palestinian Authority.