A spring-loaded bottle cap/applicator apparatus for enabling the contents at the very most bottom portion of a container such as a nail polish bottle to be reached by a brush of the apparatus. A cap assembly, a brush member, and a coil spring are disposed within the cap assembly to bias the brush member outwardly relative to the upper cap member when said cap assembly is not threadably engaged with a threaded neck portion of the container. An outwardly protruding shoulder portion disposed on a base portion of the brush member limits the outward travel of the brush member and holds the brush member captively within the cap assembly. The construction of the cap assembly, in conjunction with the construction of the brush member, enables the apparatus to be constructed simply, quickly easily, and inexpensively to produce a bottle/cap applicator which is capable of reaching the very lowermost contents of the container with which it is secured, and which is maintained at a predetermined position within the container as the cap assembly is threadably screwed onto the neck portion of the container.