The triple-time world champion struggled to produce the temperatures necessary to make best use of the ultra-soft compound tyres which saw him being knocked out in the second part of qualifying.
He started the Monte Carlo street race down in 13th place on the grid but recovered to P7 by the end of the 78-lap race.
Championship leader and Monaco GP winner Sebastian Vettel is now 25 points ahead of the nearest title rival Hamilton.
Next round is the Canadian Grand Prix and the tyre allocation is the same as the Monaco GP, which will see cars run the soft, super-soft and ultra-soft compounds.
“Coming here [to Monaco], I was thinking we would have some seriously strong races coming up with tracks I am generally strong at, but this issue with the tyres is a bit of an unknown and we’re going to the next race with the same tyre [compounds],” Hamilton said, as quoted by ESPN.
“It’s only the ultra-soft that’s been an issue, so that’s really what I have got to try and understand with the team this week.
“There’s so many different things we have got to look into to try and understand why one car could make it work and the other couldn’t,” he said, referring to teammate Valtteri Bottas’, who qualified third in Monaco under a tenth slower than Vettel.
“Whether it’s multiple laps, whether it’s backing off, utilizing the fronts more than the rears, whether it’s making a more understeer car, an oversteer car, all these different things, brake balance, all these different things, need to start looking into. I will definitely look further into it,” the former McLaren driver added.