Despite security arrangements, a large number of devotees, including those from neighbouring states, turned up to offer prayers when the shrine was opened at 5 pm.
Chief priest Vasudevan Nampoothiri opened the sanctum sanctorum in the presence of 'tantri' (head priest) Kandararu Rajeevaru.
There would be no specific pujas on Tuesday and the shrine would be closed at 10 pm with the rendition of 'harivarasanam', the customary lullaby for Lord Ayyappa, temple authorities said.
The temple would remain open for five days till February 17 for the monthly pujas during the Malayalam month of Kumbam, temple authorities said.
Several special rituals including 'kalabhabhishekam', 'sahasrakalasam' and 'laksharchana' would be performed during the five days, they said.
There has been a sense of anxiety in and around Sabarimala in view of the reopening as the shrine had witnessed frenzied protests during the recently concluded annual pilgrimage season over the entry of women of menstruating age.