Kruz was opened late in 2006 by long-time bartender and bar manager of gay bars, Jerry Breiling, and his partner Serge Bellitelli. Re-taking the building that had previously been a popular gay bar a few years earlier (known first as Gargoyles and then South Water Street Docks), the bar quickly became a favorite, taking business away especially from the Harbor Room bar (where co-owner Jerry had most recently worked).

The first summer they were open, the owners opened a large patio alongside the bar. This area quickly became a favorite outdoor patio (larger and quieter than most), and with the onset of winter, they erected a large tent over the patio area with sturdy side walls, and standing gas heaters and gas fireplaces inside. It thus was a year-round patio, especially for smokers.

One of the favorite icons of the bar has become its sheet metal cut-outs of male leathermen figures, created by a Chicago artist and often seen at the annual IML leather mart there. Another popular touch are some laser light machines, which cast blue and green stars throughout the bar. The pool table inside the bar space has clear pool balls, with glitter inside. The entire bar space is beautifully but tastefully decorated each Christmas, including a large natural tree inside the entrance.

In its (so far) years of operation, the bar has become one of gay Milwaukee's favorite destinations.

In October 2023, owner Jerry Breiling unexpectedly passed away. His partner Serge continued to operate Kruz Bar.