The environs of Ecser were inhabited even at the time of the Conquest. The name of the village probably comes from the Árpád chief family because chief Árpád's grandson's name was Ecsellő. According to another assumption, the name of the village is in relation with an oak tree (in Hungarian "cserfa") which had been the symbol on seals over centuries.

The first written sign of Ecser comes from 1315. The church was mentioned in a document in 1399. In the Middle Ages there were several landlords in Ecser but under the Turkish Empire it became totally derelict. Its lands were cultivated by the people of the neighbouring villages.

In a survey in 1696 Ecser was mentioned as an uninhabited settlement.

The re.occupation of the village started in 1699. At that time 11 families lived here in quite good living conditions. 9 local men also took part in the Rákóczy Independence War.

Ecser was purposely settled at the beggining of the 18th century. The landlord of the village, Antal Svajdler, made Slovak, and - in smaller numbers - German and Hungarian people settle down. In 1722 Antal Grassalkovich took possession of Ecser. He also made Slovak people settle down here. In 1730 50 families, all of them taxpayers, lived in the village. The new settlers mostly came from Central Slovakia, from the environs of Trencsén.

To satisfy the increasing demand, a new Catholic church in Baroque style was built on the ruins of and old chapel in 1740. Today, this is the only historic building in Ecser. Its chronicle, the so called "Historia Domus", has been written since 1757 and contains all the important events in the life of the town. The school and the rectory were built in 1740 as well.

According to a survey in 1836, there were 612 Catholic people in Ecser. 80% of them were Slovak native speakers and 20% were Hungarian. In the Independence War of 1848-49 some local men joined the army. In the spring of 1849, several Hungarian troops occupied the north part of the village and some battles in Pest and Rákos were commanded from there.

Since then, there have been many landlords in Ecser. The redistribution of the possession happened in 1852, and in 1874 most of the land became the possession of the local farmers. According to a monograph of 1877, the traditional costume of Ecser was famous at that time as well. So the origins of the world famous "Wedding in Ecser" go back to the 18th century.

The Budapest-Szolnok railway which was built in the 1880s was a landmark in the history of Ecser, but World War I put an end to the development. 52 local soldiers died in the battles. Their names are engraved on a tablet above the entrance of the church.

The mains were built up between 1930-1932, and the first call box started to work in 1937.

During World War II many people died either in battles or in the village. Their names are recorded on a monument which was built in 1996.

In 1947 there was an agreement between Czechoslovakia and Hungary. According to it 25 families returned to their homeland. In place of them, Hungarians came from Czechoslovakia. The agricultural cooperative system was founded in 1960 and it determined the agricultural development of Ecser. In the 1960s and 1970s waterpipes, a surgery, a school and a kindergarten were built. Later when the population increased they were expanded.

Ecser has a twin city in Slovakia (Zlaté Klásy) and in Turkey (Kumbag). Today, Ecser borders on Budapest. We can say that it is a suburb with 100% infrastructure. And we can say that genuine local people take care of their traditions, their customes and their "wedding" which is famous all over the world.