Not every immigration cases is successful. Every year, thousands of cases are denied by USCIS or by immigration judges.
An appeal is a petition to a higher authority to reverse a decision or a judgment.
Under U.S. immigration law, almost every petition, application or immigration court decision can be appealed. Also, Federal Courts have jurisdiction even on the non-action of immigration authorities, through a petition for a Writ of Mandamus.
The denial of family-based immigration petition, filed on Form I-130, can be appealed to the Board of Immigration Appeals (BIA). The most frequent ground for an I-130 denial is a charge of marriage fraud. Other grounds include the failure to timely respond to a Request For Evidence. In turn, BIA decisions over denied I-130 petitions can be appealed to a U.S. District Court having jurisdiction over the case.
Denied employment-based Visa petitions for temporary work Visas and permanent workers can be appealed to the Administrative Appeals Office (AAO). The decisions of the AAO can be appealed to a U.S. District Court, although Federal law gives a lot of deference to agency decisions.
Immigration courts have jurisdiction over removal (deportation) and exclusion cases. An immigration judge's decisions are always appealable to the BIA. Also, a timely-filed appeal triggers an automatic stay of removal until the BIA makes a final decision on the case. BIA decisions over removal cases can be appealed to the U.S. Court of Appeals having jurisdiction over the case.
Finally, USCIS decision denying applications for citizenship can be appealed in the U.S. District Court having jurisdiction over the case. However, before filing a Federal Court appeal is necessary to request a hearing with an immigration officer, through Form N-336, so that the requirement of exhaustion of administrative remedies can be satisfied.