Therapy planning and conducting in psychological treatment involves a systematic process through which a mental health professional assesses the individual’s problems, establishes therapeutic goals, selects appropriate techniques, and evaluates progress. In psychodiagnostics, therapy planning is closely linked with psychological assessment because accurate diagnosis and understanding of the client’s psychological functioning provide the foundation for effective treatment. The first step in planning therapy is the comprehensive assessment of the client. The psychologist collects information about the client’s personal history, family background, social environment, emotional experiences, behavioural patterns, and current difficulties. Various psychodiagnostic tools such as psychological tests, interviews, behavioural observations, personality assessments, and cognitive assessments may be used to understand the nature and severity of the problem. This assessment helps in identifying psychological disorders, strengths, coping abilities, and factors influencing the client’s difficulties. After assessment, the psychologist develops a case formulation. Case formulation is an explanation of how the