Smoking fetishism ("capnolagnia") is a sexual fetish (paraphilia), consisting of the fetishisation of the smoking of tobacco and marijuana. Among heterosexual men, the fetish is often associated with oral fixations and fellatio.

A number of smoking fetish websites and discussion groups dedicated to gay men exist. The smoking fetish in gay men appears to be somewhat different from the general smoking fetish. There seem to be several subgroups of fetishists which differ depending on what aspect of smoking they found arousing. Some involve taking pleasure in watching visually dominant men smoking. For instance, it might include big and hairy men or men in uniform smoking a cigar, although the fetish might not be linked to cigar smoking. Another subgroup involves a fascination of young men smoking (usually cigarettes).

Some of these fetishers appear to be attracted to the "innocent young man" picking up smoking and the rebellious aspects of this action. Some may link this to "growing up" and becoming a real man. The fetish might also involve a fascination with the fact that the lungs of a healthy, clean, pure body of a young man becomes filled with harmful smoke. In some cases the fetish appears to be linked with the fascination with smoke damage - the fetisher might find it arousing that a healthy man will subject himself to the damage of smoking.

In spite of these differences, most gay men smoking web sites do not cater to either subgroup. They just focus on the general aspects of the fetish by posting pictures, novels etc. so the individual user is left to find the items most appealing to him.

Some fetishists have a fascination with the addictive properties of nicotine, and its ability to cause harm, and there is a sub-fetish relating to women or men being harmed by smoking, sometimes called "lung damage". For women this is seen in videos showing women smoking and coughing, suggesting self-destructiveness. More common videos are those showing a woman or a man in bondage, being forced to smoke or to inhale smoke.

"Glamor" smoking and "dark side" smoking are the major divisions within the fetish. The glamor aspect of the fetish emphasizes the way smoking visually enhances women's sexual appeal; the dark side links smoking to female domination, bondage and domination, and sadism/masochism.

Both elements may be related to the appeal of the "bad girl" and the fantasy that even a "girl next door" type who smokes may be a tigress in the bedroom. A handful of producers specialize in videos appealing to one or both sides of the fetish.

The glamorous aspect of women' smoking traditionally has had wide appeal, among the general population as well as among those who find it sexually arousing. This appeal has always been emphasized in cigarette advertising, and undoubtedly one reason young women have been drawn to smoking cigarettes. Historically considered a masculine habit, the feminization of smoking with the advent of fashion brands specifically marketed towards women has drawn the attention of fetishists who see the use of these brands as a way for women to increase or enhance their sexual appeal. Most often this fascination is focused on young fashion-conscious professional women who are the target demographic for these brands, which are differentiated by slimness and added length over traditional brands of cigarettes. Videos for the glamor smoking fetish are typically a model or models smoking, sometimes directly to the camera (representing the viewer) but more often with the camera as an observer. Sub-fetishes may include specific cigarette brands (e.g. Marlboros, Newports), types (corks, lengths), holders (often with the woman wearing gloves), or specific methods of smoking (e.g. smoking multiple cigarettes, nostril exhaling smoke, french inhaling smoke, blowing smoke rings). Additionally, there are a plethora of web sites that have both videos and pictures of (typically) women giving oral sex whilst smoking, as well as in various sex positions, and often being ejaculated on whilst smoking.

The dark side of smoking emphasizes the dominance of the woman smoker, whether in BDSM fetish gear or as the "take charge" sadistic girlfriend. Videos produced for this aspect of the fetish often show a man in bondage with one or more women blowing smoke in his face, "ashing" him, forcing him to eat their ashes, and possibly being burned. Because of its relation to male humiliation and masochism, the dark side of the smoking fetish is most often combined with other fetishes, including corporal punishment. Dark side fetishists also include those whose attraction is to the lit cigarette (as an implement of pain) or to an ashtray of butts (as an object with which to humiliate him).