Yes, deathbed conversions are real. Christian chaplains across the country who work in hospitals regularly encounter people who are on their deathbeds and lead them to Christ. The chaplains are there not only for spiritual help and direction to people of all faiths in hospitals but also are there to present the gospel to the sick and dying. Deathbed conversions are the frequent result of their preaching the gospel.
In the mid-90s I was an orderly in a San Diego hospital. The chaplain of the hospital went to the same church that I attended. I asked him if he had had any deathbed conversions, and right away he said he had. Later, another hospital chaplain friend of mine told me the same thing.
Are deathbed conversions legitimate?
We can't say that all deathbed conversions are legitimate; but when the gospel is properly presented and people are afraid of what is coming regarding to death, many will reach out to Christ. It isn’t our place to judge their sincerity or motives. But, God saves many people whose motives may not always be pure. The Bible tells us that God will not give us a snake if we ask for a fish (Luke 11:11). In other words, God doesn’t fake a person out. If someone asks the true Jesus for salvation after hearing the real gospel, then there is no reason to doubt his or her conversion.