Cagliari is overall a tolerant city, its population is curious and welcomes changes. It can therefore be comfortably defined as gay tolerant. However, don't imagine a Mediterranean version of London or San Francisco. It certainly isn't. And although cagliaritani have grown accustomed to the presence of homosexuals as a reality of everyday professional and social life, it probably isn't ready yet for the most open displays of affection or eccentricity.
Socially speaking, there is no proper gay area or gay club in Cagliari, as you might find in many other cities. There are a number of gay-friendly bars, restaurants, hotels and B&Bs, especially around piazza Yenne.
The gay scene is nevertheless alive and kicking. There is a very active cultural organisation called ARC (Associazione Culturale Gay Lesbica Bisessuale Transgender Cagliari, www.associazionearc.eu), which is on the forefront of gay rights and anti-discrimination campaigns.