Two men are in a critical condition while six other people have been rushed to hospital from two music festivals in Sydney.

The men, aged 22 and 24, are fighting for their lives at Westmead Hospital after attending the Hardcore Till I Die festival at Sydney Olympic Park on Saturday.

A further man, in his 20s, was taken to hospital in a serious condition from the music festival, while five people have been taken to hospital from the Electric Gardens Festival in Centennial Park, including two women aged in their 60s.

Out of the eight hospitalisations, drugs are likely to have been a factor in six cases, a NSW Health spokeswoman said.

At the Electric Gardens Festival, 75 people were caught out by police for drug related offences, NSW Police said on Saturday night.

Criminal infringement notices were issued to 25 people, a further 43 people filled out court attendance notices, there were six cannabis cautions and one youth caution, a police spokeswoman said.