Apart from local pilgrims, a majority of the believers have come from Croatia, Italy, France, Germany, Austria as well as from overseas.
On Saturday, 25 June, which is the anniversary day, masses and religious services will be said in over 15 languages, with prominent Croatian Friar Zvjezdan Linic leading the central Mass at 1900 hrs.
The reported apparitions at Medjugorje have not yet been officially declared "worthy of belief" by the Catholic Church.
In 2010, the Vatican established a 17-member commission of inquiry into this matter.
The Bishops' Conference of the former Yugoslavia concluded at a convention in Zadar in 1991 that investigations conducted at the time of the apparition did not provide evidence that the events in Medjugorje were supernatural, noting that the case should continue to be followed.
Six children from Medjugorje said in 1981 that the Virgin Mary appeared to them for the first time on 24 June that year. Almost thirty years later, some of them still claim that they see apparitions of the Virgin May.
It is estimated that tens of millions of pilgrims have visited Medjugorje since then.