Human gene patents are patents on human genes that have been removed from human bodies and scientifically isolated and manipulated in a laboratory. The U.S. Patent and Trademark Office (the USPTO) has issued thousands of patents on such genes, and patents have also been granted by the European Patent Office, (the EPO). Legal and moral justification, however, are not identical, and it is possible for a legal decision to be immoral although consistent with legal precedent and procedure. So, it is surprising to learn that some people believe that the legal justification of human gene patents can remove the most serious moral objections to them. Yet, those who are well-versed in patent law often believe that confusion over some quite basic legal and scientific facts accounts for moral objections to such patents and, in particular, for the belief that they justify the ownership of one person by another. Once these confusions are removed, they contend, we will see that there is nothing especially alarming about patents on human genes, and no reason to believe them immoral. Such claims seem especially surprising because the morality of an invention is generally supposed to have little role in decisions about whether or not an invention deserves a patent under U.S. law. Although the European Patent Convention's article 53 (a) prohibits patenting inventions, the publication or exploitation of which would be contrary to public order or morality, it turns out that this clause rarely justifies withholding a patent from an invention that otherwise meets legal criteria. Thus, although more than 320,000 patents have been granted by the EPO since its creation, this clause has never been used successfully to strike down a claim for a patent. Indeed, Ulrich Schatz explains, “Poisons, explosives, extremely dangerous chemical substances, devices used in nuclear power stations, agro-chemicals, pesticides and many other things which can threaten human life or damage the environment have been patented, despite the existence of the public order and morality bar” in almost all European countries. Indeed, this paper shows, while ethical objections to human gene patents are often controversial, they need not be unreasonable, nor need they depend on mistaken assumptions about patent law. Rather, they may reflect familiar ethical concerns about the dominance of commercial imperatives in modern societies; concerns about the disparities in power and wealth amongst individuals and countries; and concerns about the lack of public discussion, transparency and accountability surrounding significant changes in people's rights, status and opportunities. Hence, I conclude, ethical concerns cannot be easily dismissed and, indeed, point to the need to think harder about the nature and justification of patent law, itself.