The present invention provides a garment useful as swimwear or sun-bathing attire that has an adjustable waistband which allows the girth of the garment and waistband to be expanded or decreased by the user, according to the body size and desired fit of the user. Swim garment includes a front panel, a rear panel, and sliding adjustable straps that connect the front panel to the rear panel. Said sliding adjustable straps permit lengthening or shortening thereof by accumulation of material, in the manner of a bra strap, and compose an adjustable section of the garment's adjustable waistband.