About one third of Germany's estimated 82 million people will be surveyed.
The last census in former West Germany took place in 1987 – also against strong protests over privacy – and the last in East Germany was held in 1981.
Anyone who is asked for information faces a fine if they refuse. Data cannot by law be shared with any other government agency, however.
Questions on the general survey include, “How many people live in your residence?”, “In which industry do you work?” and “What educational qualifications do you have?”
The questionnaire runs to 10 pages. First and foremost, authorities want to know how many people actually live in Germany and where they live.
Using this, they can determine electoral boundaries, how state financial transfers should be made, and how many seats in the federal parliament each state should have.
The European Union requires that all member states including Germany hold a census every 10 years.
Unlike previous surveys, the 2011 census won't be a full head count but rather a mixed-mode method.
About 10 percent of the general population will be interviewed by surveyors on or after Monday. They will be randomly selected and asked, among other things, about their education levels, job status and immigration background.
A separate survey will be made of collective living quarters such as student residences and aged care homes. In sensitive accommodation places such as psychiatric hospitals, refugee establishments and homes for the disabled, the facilities' managers will be asked to collect and provide the data.
Other data will come from municipalities based on the mandatory registration by all residents with local authorities. These will be used along with data from the Federal Employment Agency on all people who are subject to social insurance contributions and people who are registered as unemployed.
The census will also focus on building and housing ownership, figures for which are currently patchy. All 17.5 million owners of residential property will get a questionnaire by post, asking for information on buildings and dwellings.
The first results will be released in autumn of 2012.
Data protection advocates have raised concerns about the intrusion into people's privacy – concerns rejected by the statistics office, Destatis, which insists all data will be closely guarded and will not be shared with any other agency.
The German Working Group on Data Retention, a privacy initiative, has criticised the fact that questions are asked that go beyond what the EU requires of a census – for example the immigration background and the religion of the respondents. These answers are, however, voluntary.
The group also fears the data can be used to make inferences about individual citizens.
The 1987 census in West Germany sparked strong protests and a court challenge that eventually led to changes to the country's data laws.