Quick & Dirty:

Code:
%% LyX 1.6.4 created this file.  For more info, see http://www.lyx.org/.
%% Do not edit unless you really know what you are doing.
\documentclass[oneside,ngerman]{scrbook}
\usepackage[T1]{fontenc}
\usepackage[latin9]{inputenc}
\setcounter{secnumdepth}{3}
\setcounter{tocdepth}{3}

\makeatletter
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.
\usepackage{calc}

\makeatother

\usepackage{babel}

\begin{document}
\begin{labeling}{\bf der Bachelor-Thesis:}
\item [{\textbf{{\parbox[t]{\widthof{\bf der Bachelor-Thesis:}}{Titel der Bachelor- Thesis:}}}}] %
\parbox[t]{\linewidth}{$\,$ \\ bla bla bla  bla bla bla bla bla bla bla bla bla}
\item [{\textbf{Autor:}}] bla
\item [{\textbf{1. Prüfer:}}] bla
\item [{\textbf{Abstract:}}] bla bla bla bla bla bla bla bla bla bla bla
bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla
bla bla bla bla bla bla bla bla bla bla
\end{labeling}

\end{document}