In an interview with TerrorTrap.com, director Mark Rosman stated that he dislikes the US poster art for this film. Rosman's idea for the films poster was a Deliverance-style image of a hand rising out of the swimming pool. However the poster for the US release shows an image of a scantily-clad young woman.
Lois Kelso Hunt's performance is entirely dubbed. Her voice was deemed not "scary" enough for the role. In the Special Edition DVD from Liberation Entertainment, the film's director, Mark Rosman, comments that he believed that she had the right look for the part but ideally he would have preferred a huskier voice, Lois's voice being more high pitched than he would have liked.
The starting budget was US $125,000. The film's total budget would end up at being about US $300,000. The production had already gone over budget during preproduction and it was a cousin of director Mark Rosman who came up with enough funding to continue shooting.
The film's storyline takes place on the eve of seven sorority girls' graduation. On the Australian home video release, artwork for the movie shows a college girl dressed in black graduation gown with accompanying black mortar board. But in the film itself, when all the graduating gals are seen in graduation attire, they're all in white grad-garb.
Prior to this movie, director Mark Rosman had worked as a voluntary first assistant director and protégé to Brian De Palma on 1980's Home Movies (1979). Rosman decided that the fastest way to become a film director himself was to make a picture himself. And that movie ended up being this film.
The number of college sorority sisters seen in the film totaled to seven. Actually, the movie's Spanish title is "Siete mujeres atrapadas" which translates into English as meaning "Seven Trapped Women".
This 1983 film was part of a late 1970s-early 1980s cycle of slasher films which included such horror movies as Halloween (1978) and Friday the 13th (1980). The House on Sorority Row (1983) featured seven sorority sisters on the eve of their graduation. One of these other horror movies in this slasher cycle also had a graduation theme. Graduation Day (1981) had been made and released about two year's earlier in 1981.
The trivia items below may give away important plot points.
There was an alternate ending shot for the film. It would have followed right where the film currently ends, cutting to the police taking the dead bodies out of the swimming pool. The upside down body of a person in the clown costume was to be floating in the pool and when turned over it would reveal Katherine in the suit. This ending was rejected as being too down beat, the distributors also insisted more gore be added to the film.
The key reason the filmmakers decided to kill off Harley Jane Kozak's character Diane early in the movie was because they thought Kozak and Eileen Davidson looked too much alike due to their similar hairstyles.
In an interview with TerrorTrap.com, Mark Rosman stated that there was an additional alternate ending to the script. The original script ended with Katie in the hospital being pushed along in a wheelchair. It is then revealed that the orderly pushing her is Eric and the film ends.