The 46-truck convoy includes 5,500 food parcels for over 27,500 people, the ICRC said in a statement, while noting that one food parcel should last a family of five a month.
The convoy also brought in vital medical and surgical items such as dressing materials.
"The convoy is a positive first step and will lessen the immediate suffering of some civilians in the Eastern Ghouta region," said the ICRC's Middle East Director, Robert Mardini.
"But one convoy, however big, will never be enough given the dire conditions and shortages people are facing," he said.
The ICRC director said in the statement that repeated and continuous humanitarian access is essential and more must be granted in the coming period.
The last time the ICRC was able to deliver aid in Eastern Ghouta was on Nov. 12 last year.
The ICRC said that during the past weeks of intense fighting, many people in Eastern Ghouta have lost their lives due to the fighting or because they had no access to medical care.
Seeking shelter from continuous bombardments, families have spent days hiding in underground shelters with very little food to sustain them.
It said that Damascus city has also not been spared. Many neighborhoods have come under mortar attack in the past weeks, with civilians killed and wounded.
The ICRC said it has repeatedly called for all sides in Syria to respect the laws of war, which are being ignored and it again urged parties involved in the conflict to take every precaution to spare and protect civilians.