Despite the popular view (also present in many guides to Russia), Dagestan is not more dangerous than other places in the Caucasus. When we speak of dangerous places, we rather mean Georgia that attracts most of the tourists from Europe and where we actually risk being robbed or assaulted.
Obviously, the situation in Dagestan is far from being entirely stable (although it has been improving recently). Tourists run only minimal risks connected to internal political conflicts. The greatest difficulties, connected to the political situation, are the numerous checkpoints on the roads and police patrols that often check documents and ask about your travel destination and other details. However, usually they do not cause any major problems for the tourists.
The safest region in Dagestan are the mountains, where the situation is peaceful and the people are very hospitable and open. On the other hand, it is better to steer clear of Khasav-Yurt city and region, and the area around Buynaksk, where clashes between guerrillas and the army happen once in a while. Besides, to enter the regions bordering Georgia and Azerbaijan you will need a special permit issued by the Federal Security Service.
Women should not travel alone; they will be picked up persistently.
There are no exotic illnesses in Dagestan, so you needn’t get vaccinated against them before travelling there.