At the end of 2017, only around 7,000 prostitutes were validly registered with the authorities nationwide and 1,350 prostitution trades were permitted. 
According to the Federal Statistical Office, around 40,400 people in Germany were registered in the prostitution industry at the end of 2019. 19% of the prostitutes had German citizenship (7700), 35% Romanian, 11% Bulgarian and 8% Hungarian. Of the registered prostitutes, 78% were between 21 and 44 years old, 17% were 45 years or older, 5% were between the ages of 18 and 20. A total of 2170 prostitution businesses were registered, 93% of them brothels. 140 permits were required for prostitution agencies, vehicles and events. 
According to a non-representative survey by the German Ministry of Family Affairs of 110 prostitutes in 2004, the women questioned were three times as likely to be victims of physical violence and five times as likely to be victims of sexual violence as the average female population.  The study claims that “after the Prostitution Act came into force in 2002, the very high level of physical, sexual and psychological violence among prostitutes both in the work context and in the private sphere continues to exist and no downward trend is evident”.  According to this study, prostitutes also had an increased risk of multiple victimization. They were more likely to suffer serious injuries and seek medical or police assistance less often.  The following statistics were collected in the study:
The findings of the study by the Ministry of Family Affairs largely coincide with those of another study from the German-speaking area from 2001 (98% of prostitute women had at least one traumatic experience, most of them several; 70% had experienced physical attacks; 68% had been raped mostly by clients; 59% were diagnosed with post-traumatic stress disorder, 50% had experienced abuse as children). 
An evaluation of the German Prostitution Act by the Family Ministry in 2007 came to the conclusion that the legalization of prostitution had barely improved the living conditions of prostitutes, if at all. 
Parts of this article seem out of date as of 2014.
Please help to research and insert the missing information.
There is clear disagreement in the political and social debate about absolute figures in connection with prostitution as well as the relative extent of criminal structures and the best ways to combat them.  However, there is a general consensus among the parties represented in the Bundestag that there is a need for regulation in order to be able to combat crime in the red-light district more effectively and to better protect victims from perpetrators.
A central cause lies in the extent of the unreported areas of sexual exploitation offenses (Sections 180a, 181a, 232 and 233a StGB). The federal government has so far not had any relevant studies or plans.  Sabine Constabel, social worker in the department of social services for prostitutes in the city of Stuttgart, claims that prostitution cannot be relegated to the dark field because it is absolutely dependent on advertising. If a client can find prostitutes, so can the police. 
In 2008, the then head of the Augsburg Criminal Police, Klaus Bayerl, said that the large brothels that had been created in the years since 2002 are facilities in which the official managing directors are straw people, while the responsible persons who actually act in the background come directly from the pimp or serious criminal milieu and almost always had close ties to organized crime. 
In the area of crime related to prostitution and nightlife, pressure was put on alleged victims in 2005 to refuse to testify. Of 642 alleged victims, 325 (approx. 50%) were questioned by the police on this matter. In 93 (approx. 15% of the total number of alleged victims, approx. 29% of the questioned alleged victims), the police found indications of inadmissible interference.  The feminist magazine Emma also criticized in 2013 that the police were unable to guarantee adequate protection. 
Several outlaw motorcycle gangs are among the competitors for supremacy in the red light district. Again and again there were massive clashes between the Bandidos and the Hells Angels. Both associations are assigned arms and drug trafficking and the promotion of prostitution.   
In some places the Black Jackets are involved in the struggle for control of the red light district (as of 2013).  In 2013 the brothel Lustpark der Black Jackets in Neu-Ulm was excavated and an arsenal was secured.   In 2012 it became known to the public that the Dutch rocker organization Satudarah MC was performing in Germany.  Satudarah is deeply involved in prostitution, drug trafficking, and violent crime.