The fishermen, who were in a group of eight, were caught by Qatar coastguards on June 2, local media reports said. Those given one-month sentence were identified as Silvapillai Rajaratnam, Mois Pappiose, Alphons Raj, Maria Robin Raj and Robin Pious.
Indian ambassador Deepa Gopalan Wadhwa stressed that fishermen should be aware of the implications of crossing international waters.
"Most of the fishermen stray into Qatari waters unintentionally due to weather conditions or other problems.
The embassy and community here are always ready to help them if they are detained by the officials," she said "But there are judicial procedures and legal action they will have to face. If they are detained or imprisoned, their livelihood is affected, hence they should be careful," she was quoted by The Peninsula as saying.
The cases related to the three other members of the group, vessel's captain Maria Vitamind, Nelson Babu and Stephen Raj, will be taken up on July 21.
Dozens of fishermen from neighbouring countries have been regularly arrested by Qatar's coastguards for reportedly entering Qatari waters illegally.
Some 34 Indians including three females are currently serving sentences in prisons here, while some 150 including eight women are at the deportation centre.